U.S. patent number 8,504,716 [Application Number 12/575,278] was granted by the patent office on 2013-08-06 for systems and methods for allocating bandwidth by an intermediary for flow control.
This patent grant is currently assigned to Citrix Systems, Inc. The grantee listed for this patent is Henry Collins, Allen R. Samuels. Invention is credited to Henry Collins, Allen R. Samuels.
United States Patent |
8,504,716 |
Samuels , et al. |
August 6, 2013 |
Systems and methods for allocating bandwidth by an intermediary for
flow control
Abstract
The present disclosure is directed towards systems and methods
for allocating a bandwidth credit or an annuity of bandwidth credit
to a sender by an intermediary deployed between the sender and a
receiver. The sender may be allocated a bandwidth credit or an
annuity of bandwidth credit which may identify an amount of data
the sender may transmit over a predetermined time period to the
receiver, via the intermediary. The intermediary may determine an
allocation of a one-time bandwidth credit based on the
determination that a difference between the rate of transmission of
the sender and the bandwidth usage of the sender falls below a
predetermined threshold of the bandwidth credit. The intermediary
may determine an annuity of bandwidth credit based on a
determination that a difference between the bandwidth usage of the
sender over the annuity period and the annuity of bandwidth credit
exceeds a predetermined threshold.
Inventors: |
Samuels; Allen R. (San Jose,
CA), Collins; Henry (Bucks, GB) |
Applicant: |
Name |
City |
State |
Country |
Type |
Samuels; Allen R.
Collins; Henry |
San Jose
Bucks |
CA
N/A |
US
GB |
|
|
Assignee: |
Citrix Systems, Inc (Fort
Lauderdale, FL)
|
Family
ID: |
41351615 |
Appl.
No.: |
12/575,278 |
Filed: |
October 7, 2009 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20100095021 A1 |
Apr 15, 2010 |
|
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
61103712 |
Oct 8, 2008 |
|
|
|
|
Current U.S.
Class: |
709/235;
709/233 |
Current CPC
Class: |
H04L
47/781 (20130101); H04L 47/822 (20130101); H04L
47/724 (20130101); H04L 47/70 (20130101); H04L
47/762 (20130101); H04L 47/826 (20130101) |
Current International
Class: |
G06F
15/16 (20060101) |
Field of
Search: |
;709/235,233 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
WO-03001748 |
|
Jan 2003 |
|
WO |
|
WO-03/096647 |
|
Nov 2003 |
|
WO |
|
WO-2004/028175 |
|
Apr 2004 |
|
WO |
|
Other References
International Preliminary Report on Patentability on
PCT/US2009/059788 dated Apr. 21, 2011. cited by applicant .
International Search Report on PCT/US2009/059788 dated Dec. 14,
2009. cited by applicant .
Written Opinion on PCT/US2009/059788 dated Dec. 14, 2009. cited by
applicant.
|
Primary Examiner: Shingles; Kristie
Attorney, Agent or Firm: Foley and Lardner LLP McKenna;
Christopher J.
Parent Case Text
RELATED APPLICATION
This application claims priority to U.S. Provisional Application
No. 61/103,712, entitled "Systems And Methods For Allocating
Bandwidth By An Intermediary For Flow Control", filed on Oct. 8,
2008, which is incorporated herein by reference in its entirety.
Claims
What is claimed is:
1. A method for allocating, by an intermediary device between a
sender and one or more receivers, a bandwidth credit of the sender
by comparing the allocated bandwidth credit to a measurement of
data transmission rates via the intermediary device and compression
of data by the intermediary, the method comprising: a) allocating,
to a sender, a bandwidth credit identifying an amount of data the
sender may transmit over a predetermined time period to the one or
more receivers via an intermediary device, the intermediary device
compressing data of the sender transmitted to the one or more
receivers; b) monitoring, by the intermediary device, bandwidth
usage by determining a ratio of compression of data of the sender
compressed by the intermediary device and a rate of transmission of
compressed data of the sender transmitted by the intermediary
device to the one or more receivers; c) determining, by the
intermediary device, that a difference between the rate of
transmission of the sender and the bandwidth usage of the sender
falls below a predetermined threshold of the bandwidth credit; and
d) communicating, by the intermediary device responsive to the
determination, an allocation of a one-time bandwidth credit to the
sender based on the difference.
2. The method of claim 1, wherein step (a) further comprises
allocating, to a plurality of senders, a plurality of bandwidth
credits, each of the plurality of bandwidth credits identifying an
amount of data each of the plurality of senders may transmit over a
predetermined time period to at least one receiver.
3. The method of claim 1, wherein step (c) further comprises
determining, by the intermediary, that the difference between the
rate of transmission of the sender and the bandwidth usage of the
sender falls within a predetermined threshold range of the
bandwidth credit.
4. The method of claim 1, further comprising identifying, by the
one-time bandwidth credit, a second predetermined amount of data
the sender may send to the one or more receivers within the
predetermined time period.
5. The method of claim 1, further comprising identifying, by the
one-time bandwidth credit, a second predetermined amount of data
the sender may send to the one or more receivers within a second
predetermined amount of time.
6. The method of claim 1, further comprising identifying, by the
one-time bandwidth credit, a predetermined amount of additional
data the sender may send to an identified receiver via the
intermediary.
7. The method of claim 1, wherein step (b) further comprises
monitoring, by the intermediary, the bandwidth usage by determining
a rate of transmission of data transmitted from the one or more
receivers via the intermediary to the sender.
8. The method of claim 1, further comprising determining, by the
intermediary in response to monitoring, that a difference between
the rate of transmission of the sender and the bandwidth usage of
the sender falls below a predetermined threshold of the bandwidth
credit.
9. The method of claim 1, further comprising: e) allocating, to a
receiver, a second bandwidth credit identifying an amount of data
the receiver may transmit over a predetermined time period to the
sender via the intermediary; f) monitoring, by the intermediary,
bandwidth usage of the receiver by determining a ratio of
compression of data of the receiver compressed by the intermediary
and a rate of transmission of compressed data of the receiver
transmitted by the intermediary to the sender; g) determining, by
the intermediary, that a second difference between the rate of
transmission of the receiver and the bandwidth usage of the
receiver falls below a second predetermined threshold of the second
bandwidth credit; and h) communicating, by the intermediary
responsive to the determination, an allocation of a second one-time
bandwidth credit to the receiver.
10. A method for renewing, by an intermediary device between a
sender and one or more receivers, an annuity of bandwidth credit of
the sender by comparing the allocated bandwidth credit to a
measurement of data transmission rate via the intermediary device
and compression of data by the intermediary device, the method
comprising steps of: a) allocating, to a sender, an annuity of
bandwidth credit identifying an amount of data the sender may
transmit within a predetermined annuity period to one or more
receiver via an intermediary device, the intermediary device
compressing data of the sender transmitted to the one or more
receivers; b) monitoring, by the intermediary device, bandwidth
usage of the sender between the intermediary device and the one or
more receivers over the predetermined annuity period based on
determining a ratio of compression of data of the sender compressed
by the intermediary device and a rate of transmission of compressed
data of the sender transmitted by the intermediary device; c)
determining, by the intermediary device, that a difference between
the bandwidth usage of the sender over the annuity period and the
annuity of bandwidth credit exceeds a predetermined threshold; and
d) communicating, by the intermediary device responsive to the
determination, a renewed allocation of the annuity bandwidth credit
to the sender based on a second predetermined ratio of
compression.
11. The method of claim 10, further comprising identifying, by the
annuity of bandwidth credit, a plurality of amounts of data the
sender may transmit over a plurality of predetermined annuity
periods.
12. The method of claim 10, wherein step (b) further comprising
monitoring, by the intermediary, bandwidth usage of the sender
between the intermediary and the one or more receivers over the
predetermined annuity period based on determining a ratio of
compression of data of the sender compressed by the intermediary
and a rate of transmission of compressed data of the sender
transmitted by the intermediary.
13. The method of claim 10, further comprising identifying, by the
renewed allocation, a second amount of data the sender may transmit
over a second predetermined annuity period via the
intermediary.
14. The method of claim 10, further comprising identifying, by the
renewed allocation, a second amount of data the sender may transmit
over the predetermined annuity period via the intermediary.
15. The method of claim 10, further comprising: e) allocating, to a
receiver, a second annuity of bandwidth credit identifying an
amount of data the receiver may transmit over a second
predetermined annuity period to the sender via the intermediary; f)
monitoring, by the intermediary, a second bandwidth usage of the
receiver between the intermediary and the sender over the second
predetermined annuity period based on determining a ratio of
compression of data of the receiver compressed by the intermediary
and a rate of transmission of compressed data of the receiver
transmitted by the intermediary; g) determining, by the
intermediary, that a difference between the second bandwidth usage
and the second annuity of bandwidth credit exceeds a predetermined
threshold; and h) communicating, by the intermediary responsive to
the determination, a second renewed allocation of the annuity
bandwidth credit to the receiver.
16. An intermediary device between a sender and one or more
receivers for providing a change in bandwidth allocation of a
sender using a measurement of data transmission rate via the
intermediary device and compression of data by the intermediary
device, the intermediary device comprising: a bandwidth allocator
allocating to a sender a bandwidth credit identifying an amount of
data the may transmit over a predetermined time period via the
intermediary device, the intermediary device compressing data of
the sender transmitted to one or more receivers; a bandwidth
monitor monitoring bandwidth usage by determining a ratio of
compression of data of the sender compressed by the intermediary
device and a rate of transmission of compressed data of the sender
transmitted by the intermediary device; a flow controller
determining that a difference between the rate of transmission of
the sender and the bandwidth usage of the sender falls below a
predetermined threshold of the bandwidth credit; and wherein the
intermediary device communicates, in response to the determination,
a change in the bandwidth credit to the sender based on the
difference.
17. The intermediary of claim 16, wherein the flow controller
determines that a difference between the bandwidth usage of the
sender over the predetermined time period and the bandwidth credit
exceeds a predetermined threshold; and the intermediary
communicating, responsive to the determination, a renewal of the
bandwidth credit to the sender, the renewal of the bandwidth credit
identifying an amount of data the sender may transmit within a
second predetermined time period via the intermediary.
18. The intermediary of claim 16, wherein the flow controller
determines that the difference between the rate of transmission of
the sender and the bandwidth usage of the sender falls within a
predetermined threshold range of the bandwidth credit.
19. The intermediary of claim 16, wherein the bandwidth allocator
determines a one-time bandwidth credit and responsive to the
determination the intermediary communicates the one-time bandwidth
credit to the sender.
20. The intermediary of claim 17, wherein the flow controller
monitors the bandwidth usage of the sender between the intermediary
and the one or more receivers over the predetermined annuity period
based on determining a ratio of compression of data of the sender
compressed by the intermediary and a rate of transmission of
compressed data of the sender received by the one or more
receivers.
Description
FIELD OF THE INVENTION
The present application generally relates to data communication
networks. In particular, the present application relates to systems
and methods for flow control of data communicated over a network
using a network structure component, such as an intermediary.
BACKGROUND OF THE INVENTION
Network traffic may be transmitted over a network between clients
and servers traversing one or more network-infrastructure
components. Each of the clients may transmit different size data to
the servers as well as transmit as different transmission rates.
Likewise, each of the servers may transmit different amounts of
data and transmit at different transmission rates to one or more
clients. The network-infrastructure components may process the
network traffic further to cause changes to the size of data and
transmission rate of data between the clients and servers. The
clients and servers may not be aware of the changes occurring from
processing by the network-infrastructure components. Any management
of bandwidth from a client or server perspective may be challenging
or ineffective as the network-infrastructure components impact the
use of bandwidth between the clients and servers. For example, if
the data stream is compressed by a network component with a
compression format in which the compression ratios of the
compressed data packets vary, the bandwidth use also varies
accordingly.
BRIEF SUMMARY OF THE INVENTION
In the present solution, one or more intermediaries may intercept
the data transmitted between the client and the server and direct
the data's flow. An intermediary may determine the bandwidth used
by the client and the server, as well as the bandwidth available,
based on monitoring of the bandwidth between the sender and the
receiver, or even monitoring of the network as a whole. Sometimes,
in response to the monitoring, the intermediary may determine that
an additional transmission of data from the client to the server is
possible. In some embodiments, the intermediary may determine that
an additional amount of bandwidth over a predetermined period of
time for the client to send to the server is possible. In such
instances, the intermediary may utilize bandwidth monitoring to
determine a bandwidth credit which may identify an amount of
additional data the sender may transmit to the server via the
intermediary. In some embodiments, the intermediary may utilize
bandwidth monitoring to determine an annuity of bandwidth credit
which may identify an amount of bandwidth the client may use for a
predetermined amount of time.
The present disclosure thus also relates to systems and methods for
allocation of bandwidth credit or the annuity of bandwidth credit
based on the monitored information. The monitored information may
comprise information on bandwidth metrics relating to the client,
the server and the network. The bandwidth credit may identify the
amount of data which may be transferred over the intermediary in a
one-time transmission or over a period of time. Therefore, the
methods and systems disclosed address the issue of efficient data
flow control of the compressed data stream while maximizing the
efficiency and full utilization of the network's available
resources.
In some aspects, the present solution is related to systems and
methods method for allocating bandwidth credit of a sender by
comparing the allocated bandwidth credit to a measurement of data
transmission rate via the intermediary and compression of data by
the intermediary. In some embodiments, the present solution is
related to an intermediary for allocating bandwidth credit of a
sender by comparing the allocated bandwidth credit to a measurement
of data transmission rate via the intermediary and compression of
data by the intermediary. The present solution also relates to
allocating a bandwidth credit to a sender or a receiver. The
bandwidth credit may identify of an amount of data the sender may
transmit over a predetermined time period to the one or more
receivers via an intermediary. The intermediary may compress data
of the sender transmitted to the at least one receiver using any
compression method or any compression ratio. In some embodiments
the intermediary may be monitoring bandwidth usage by determining a
ratio of compression of data of the sender compressed by the
intermediary and a rate of transmission of compressed data of the
sender transmitted by the intermediary. The data of the sender may
be transmitted by the intermediary to one or more receivers. The
intermediary may determine that a difference between the rate of
transmission of the sender and the bandwidth usage of the sender
falls below a predetermined threshold of the bandwidth credit. The
intermediary may, in response to the determination, communicate an
allocation of a one-time bandwidth credit to the sender based on
the difference.
In some embodiments, the intermediary may allocate to a plurality
of senders a plurality of bandwidth credits. Each of the plurality
of bandwidth credits may further identify an amount of data each of
the plurality of senders may transmit over a predetermined time
period to one or more receivers. In some embodiments, the
intermediary may determine that the difference between the rate of
transmission of the sender and the bandwidth usage of the sender
falls within a predetermined threshold range of the bandwidth
credit. In many embodiments, the one-time bandwidth credit may
further identify a second predetermined amount of data the sender
may send to one or more receivers within the predetermined time
period. In some embodiments, the one-time bandwidth credit further
identifies a second predetermined amount of data the sender may
send to one or more receivers within a second predetermined amount
of time. In a plurality of embodiments, the one-time bandwidth
credit further identifies a predetermined amount of additional of
data the sender may send to a second group of one or more receivers
via the intermediary. In a variety of embodiments, the intermediary
monitors the bandwidth usage by determining a rate of transmission
of data of one or more receivers and transmitted by the
intermediary to the sender. In a number of embodiments, the
intermediary determines, in response to monitoring, that a
difference between the rate of transmission of the sender and the
bandwidth usage of the sender falls below a predetermined threshold
of the bandwidth credit.
In many embodiments, the intermediary allocates to one or more
receivers a second bandwidth credit identifying an amount of data
one or more receivers may transmit over a predetermined time period
to the at least one sender. The intermediary may monitor the
bandwidth usage of one or more receivers by determining a ratio of
compression of data of the one or more receivers compressed by the
intermediary and a rate of transmission of compressed data of the
one or more receivers transmitted by the intermediary to one or
more senders. The intermediary determines that a second difference
between the rate of transmission of the one or more receivers and
the bandwidth usage of one or more receivers falls below a second
predetermined threshold of the second bandwidth credit. The
intermediary, in response to the determination, may communicate an
allocation of a second one-time bandwidth credit to the one or more
receivers.
In some aspects, the present solution is related to systems and
methods for renewing an annuity of bandwidth credit of the sender
by determining the allocated bandwidth credit to a measurement of
data transmission rate via the intermediary and compression of data
by the intermediary. In some embodiments, the present disclosure is
related to an intermediary for renewing an annuity of bandwidth
credit of the sender by determining the allocated bandwidth credit
to a measurement of data transmission rate via the intermediary and
compression of data by the intermediary. In some embodiments, the
intermediary is allocating an annuity of bandwidth credit to a
sender. The annuity of bandwidth credit may identify an amount of
data the sender may transmit within a predetermined annuity period
to one or more receivers via an intermediary. In some embodiments,
the intermediary monitors a bandwidth usage of the sender between
the intermediary and one or more receivers over the predetermined
annuity period based on determining a ratio of compression of data
of the sender compressed by the intermediary and a rate of
transmission of compressed data of the sender transmitted by the
intermediary. In a number of embodiments, the intermediary
determines that a difference between the bandwidth usage of the
sender over the annuity period and the annuity of bandwidth credit
exceeds a predetermined threshold. The intermediary may
communicate, in response to the determination, a renewed allocation
of the annuity bandwidth credit to the sender based on a second
predetermined ratio of compression.
In some embodiments, the annuity of bandwidth credit further
identifies a plurality of amounts of data the sender may transmit
over a plurality of predetermined annuity periods to one or more
receivers. In many embodiments, the intermediary monitors the
bandwidth usage of the sender between the intermediary and one or
more receivers over the predetermined annuity period based on
determining a ratio of compression of data of the sender compressed
by the intermediary and a rate of transmission of compressed data
of the sender received by one or more receivers. In a number of
embodiments, the renewed allocation further identifies a second
amount of data the sender may transmit over a second predetermined
annuity period to one or more receivers via an intermediary. The
renewed allocation may also further identify a second amount of
data the sender may transmit over the predetermined annuity period
to one or more receivers via an intermediary.
In some embodiments, the one or more receivers are allocated a
second annuity of bandwidth credit identifying an amount of data a
receiver may transmit over a second predetermined annuity period to
the sender via the intermediary. The intermediary may monitor a
second bandwidth usage of the one or more receivers between the
intermediary and the sender over the second predetermined annuity
period based on determining a ratio of compression of data of one
or more receivers compressed by the intermediary. The intermediary
may also monitor a second bandwidth usage of a receiver by
determining a rate of transmission of compressed data of the one or
more receivers transmitted by the intermediary. In some
embodiments, the intermediary determines that a difference between
the second bandwidth usage and the second annuity of bandwidth
credit exceeds a predetermined threshold or is within a
predetermined threshold range. In response to the determination,
the intermediary may communicate a second renewed allocation of the
annuity bandwidth credit to one or more receivers.
In some aspects, the present solution relates to a system and
method for establishing one of a bandwidth credit or the annuity of
a bandwidth credit of one or more senders using a measurement of
data transmission rate via the intermediary and compression of data
by the intermediary. A bandwidth allocator of an intermediary, in
some embodiments, allocates to one or more senders a bandwidth
credit identifying an amount of data one or more senders may
transmit over a predetermined time period to one or more receivers
via an intermediary. A bandwidth monitor of the intermediary may
monitor the bandwidth usage by determining a ratio of compression
of data of the sender compressed by the intermediary and a rate of
transmission of compressed data of the sender transmitted by the
intermediary to one or more receivers. In some embodiments, a flow
controller of the intermediary determines that a difference between
the rate of transmission of the sender and the bandwidth usage of
the sender falls below a predetermined threshold of the bandwidth
credit. In many embodiments, the network optimization engine
communicates, in response the determination, an allocation of a
one-time bandwidth credit to the sender based on the
difference.
Any embodiment mentioned or described herein may be combined with
any other embodiment mentioned or described to create any
combination of embodiments or functionalities of the embodiments.
The details of embodiments of the disclosure are set forth in the
accompanying drawings and the description below.
BRIEF DESCRIPTION OF THE FIGURES
The foregoing and other objects, aspects, features, and advantages
of the disclosure will become more apparent and better understood
by referring to the following description taken in conjunction with
the accompanying drawings, in which:
FIG. 1A is a block diagram illustrating some embodiments of a
network environment for a client to access a server via one or more
network optimization appliances;
FIG. 1B is a block diagram illustrating some embodiments of a
network environment for a client to access a server via one or more
network optimization appliances in conjunction with other network
appliances;
FIG. 1C is a block diagram illustrating some embodiments of a
network environment for a client to access a server via a single
network optimization appliance deployed stand-alone or in
conjunction with other network appliances;
FIG. 1E is a block diagram illustrating some embodiments of a
computing device;
FIG. 2A is a block diagram illustrating some embodiments of an
appliance for processing communications between a client and a
server;
FIG. 2B is a block diagram illustrating some embodiments of a
client and/or server deploying the network optimization features of
the appliance;
FIG. 3 is a block diagram illustrating some embodiments of a client
for communicating with a server using the network optimization
feature;
FIG. 4 is a block diagram illustrating some embodiments of a sender
such as a client transmitting a data stream to a receiver, such as
a server via an appliance 200.
FIG. 5 is a flow diagram illustrating some embodiments of a method
for a flow control of a data stream communicated via a network
between a client and a server.
FIG. 6 is a flow diagram illustrating some embodiments of a client
or a server side method for a flow control of a data stream
communicated via a network between a client and a server.
FIG. 7 is a is a block diagram illustrating some embodiments of
bandwidth allocation relating to a communication between a sender
and a receiver.
FIG. 8 is a flow diagram illustrating some embodiments of a method
for bandwidth allocation relating to a communication between a
sender and a receiver.
The features and advantages of the present disclosure will become
more apparent from the detailed description set forth below when
taken in conjunction with the drawings, in which like reference
characters identify corresponding elements throughout. In the
drawings, like reference numbers generally indicate identical,
functionally similar, and/or structurally similar elements.
DETAILED DESCRIPTION OF THE INVENTION
For purposes of reading the description of the various embodiments
of the present disclosure below, the following descriptions of the
sections of the specification and their respective contents may be
helpful: Section A describes a network environment and computing
environment useful for practicing an embodiment of the present
disclosure; Section B describes embodiments of a system and
appliance architecture for accelerating delivery of a computing
environment to a remote user; Section C describes embodiments of a
client agent for accelerating communications between a client and a
server; and Section D describes embodiments of systems and methods
for a more efficient control of a flow of a data stream
communicated via a network between a client and a server and
traversing an intermediary. Section E describes embodiments of
systems and methods for allocation of bandwidth credit and
allocation of annuity of bandwidth credit to a sender transmitting
a data, via an intermediary, to a receiver on a network. A. Network
and Computing Environment
Prior to discussing the specifics of embodiments of the systems and
methods of an appliance and/or client, it may be helpful to discuss
the network and computing environments in which such embodiments
may be deployed. Referring now to FIG. 1A, an embodiment of a
network environment is depicted. In brief overview, the network
environment has one or more clients 102a-102n (also generally
referred to as local machine(s) 102, or client(s) 102) in
communication with one or more servers 106a-106n (also generally
referred to as server(s) 106, or remote machine(s) 106) via one or
more networks 104, 104', 104''. In some embodiments, a client 102
communicates with a server 106 via one or more network optimization
appliances 200, 200' (generally referred to as appliance 200). In
one embodiment, the network optimization appliance 200 is designed,
configured or adapted to optimize Wide Area Network (WAN) network
traffic. In some embodiments, a first appliance 200 works in
conjunction or cooperation with a second appliance 200' to optimize
network traffic. For example, a first appliance 200 may be located
between a branch office and a WAN connection while the second
appliance 200' is located between the WAN and a corporate Local
Area Network (LAN). The appliances 200 and 200' may work together
to optimize the WAN related network traffic between a client in the
branch office and a server on the corporate LAN.
Although FIG. 1A shows a network 104, network 104' and network
104'' (generally referred to as network(s) 104) between the clients
102 and the servers 106, the clients 102 and the servers 106 may be
on the same network 104. The networks 104, 104', 104'' can be the
same type of network or different types of networks. The network
104 can be a local-area network (LAN), such as a company Intranet,
a metropolitan area network (MAN), or a wide area network (WAN),
such as the Internet or the World Wide Web. The networks 104, 104',
104'' can be a private or public network. In one embodiment,
network 104' or network 104'' may be a private network and network
104 may be a public network. In some embodiments, network 104 may
be a private network and network 104' and/or network 104'' a public
network. In another embodiment, networks 104, 104', 104'' may be
private networks. In some embodiments, clients 102 may be located
at a branch office of a corporate enterprise communicating via a
WAN connection over the network 104 to the servers 106 located on a
corporate LAN in a corporate data center.
The network 104 may be any type and/or form of network and may
include any of the following: a point to point network, a broadcast
network, a wide area network, a local area network, a
telecommunications network, a data communication network, a
computer network, an ATM (Asynchronous Transfer Mode) network, a
SONET (Synchronous Optical Network) network, a SDH (Synchronous
Digital Hierarchy) network, a wireless network and a wireline
network. In some embodiments, the network 104 may comprise a
wireless link, such as an infrared channel or satellite band. The
topology of the network 104 may be a bus, star, or ring network
topology. The network 104 and network topology may be of any such
network or network topology as known to those ordinarily skilled in
the art capable of supporting the operations described herein.
As depicted in FIG. 1A, a first network optimization appliance 200
is shown between networks 104 and 104' and a second network
optimization appliance 200' is also between networks 104' and
104''. In some embodiments, the appliance 200 may be located on
network 104. For example, a corporate enterprise may deploy an
appliance 200 at the branch office. In other embodiments, the
appliance 200 may be located on network 104'. In some embodiments,
the appliance 200' may be located on network 104' or network 104''.
For example, an appliance 200 may be located at a corporate data
center. In one embodiment, the appliance 200 and 200' are on the
same network. In another embodiment, the appliance 200 and 200' are
on different networks.
In one embodiment, the appliance 200 is a device for accelerating,
optimizing or otherwise improving the performance, operation, or
quality of service of any type and form of network traffic. In some
embodiments, the appliance 200 is a performance enhancing proxy. In
other embodiments, the appliance 200 is any type and form of WAN
optimization or acceleration device, sometimes also referred to as
a WAN optimization controller. In one embodiment, the appliance 200
is any of the product embodiments referred to as WANScaler
manufactured by Citrix Systems, Inc. of Ft. Lauderdale, Fla. In
other embodiments, the appliance 200 includes any of the product
embodiments referred to as BIG-IP link controller and WANjet
manufactured by F5 Networks, Inc. of Seattle, Wash. In another
embodiment, the appliance 200 includes any of the WX and WXC WAN
acceleration device platforms manufactured by Juniper Networks,
Inc. of Sunnyvale, Calif. In some embodiments, the appliance 200
includes any of the steelhead line of WAN optimization appliances
manufactured by Riverbed Technology of San Francisco, Calif. In
other embodiments, the appliance 200 includes any of the WAN
related devices manufactured by Expand Networks Inc. of Roseland,
N.J. In one embodiment, the appliance 200 includes any of the WAN
related appliances manufactured by Packeteer Inc. of Cupertino,
Calif., such as the PacketShaper, iShared, and SkyX product
embodiments provided by Packeteer. In yet another embodiment, the
appliance 200 includes any WAN related appliances and/or software
manufactured by Cisco Systems, Inc. of San Jose, Calif., such as
the Cisco Wide Area Network Application Services software and
network modules, and Wide Area Network engine appliances.
In some embodiments, the appliance 200 provides application and
data acceleration services for branch-office or remote offices. In
one embodiment, the appliance 200 includes optimization of Wide
Area File Services (WAFS). In another embodiment, the appliance 200
accelerates the delivery of files, such as via the Common Internet
File System (CIFS) protocol. In other embodiments, the appliance
200 provides caching in memory and/or storage to accelerate
delivery of applications and data. In one embodiment, the appliance
205 provides compression of network traffic at any level of the
network stack or at any protocol or network layer. In another
embodiment, the appliance 200 provides transport layer protocol
optimizations, flow control, performance enhancements or
modifications and/or management to accelerate delivery of
applications and data over a WAN connection. For example, in one
embodiment, the appliance 200 provides Transport Control Protocol
(TCP) optimizations. In other embodiments, the appliance 200
provides optimizations, flow control, performance enhancements or
modifications and/or management for any session or application
layer protocol. Further details of the optimization techniques,
operations and architecture of the appliance 200 are discussed
below in Section B.
Still referring to FIG. 1A, the network environment may include
multiple, logically-grouped servers 106. In these embodiments, the
logical group of servers may be referred to as a server farm 38. In
some of these embodiments, the serves 106 may be geographically
dispersed. In some cases, a farm 38 may be administered as a single
entity. In other embodiments, the server farm 38 comprises a
plurality of server farms 38. In one embodiment, the server farm
executes one or more applications on behalf of one or more clients
102.
The servers 106 within each farm 38 can be heterogeneous. One or
more of the servers 106 can operate according to one type of
operating system platform (e.g., WINDOWS NT, manufactured by
Microsoft Corp. of Redmond, Wash.), while one or more of the other
servers 106 can operate on according to another type of operating
system platform (e.g., Unix or Linux). The servers 106 of each farm
38 do not need to be physically proximate to another server 106 in
the same farm 38. Thus, the group of servers 106 logically grouped
as a farm 38 may be interconnected using a wide-area network (WAN)
connection or metropolitan-area network (MAN) connection. For
example, a farm 38 may include servers 106 physically located in
different continents or different regions of a continent, country,
state, city, campus, or room. Data transmission speeds between
servers 106 in the farm 38 can be increased if the servers 106 are
connected using a local-area network (LAN) connection or some form
of direct connection.
Servers 106 may be referred to as a file server, application
server, web server, proxy server, or gateway server. In some
embodiments, a server 106 may have the capacity to function as
either an application server or as a master application server. In
one embodiment, a server 106 may include an Active Directory. The
clients 102 may also be referred to as client nodes or endpoints.
In some embodiments, a client 102 has the capacity to function as
both a client node seeking access to applications on a server and
as an application server providing access to hosted applications
for other clients 102a-102n.
In some embodiments, a client 102 communicates with a server 106.
In one embodiment, the client 102 communicates directly with one of
the servers 106 in a farm 38. In another embodiment, the client 102
executes a program neighborhood application to communicate with a
server 106 in a farm 38. In still another embodiment, the server
106 provides the functionality of a master node. In some
embodiments, the client 102 communicates with the server 106 in the
farm 38 through a network 104. Over the network 104, the client 102
can, for example, request execution of various applications hosted
by the servers 106a-106n in the farm 38 and receive output of the
results of the application execution for display. In some
embodiments, only the master node provides the functionality
required to identify and provide address information associated
with a server 106' hosting a requested application.
In one embodiment, the server 106 provides functionality of a web
server. In another embodiment, the server 106a receives requests
from the client 102, forwards the requests to a second server 106b
and responds to the request by the client 102 with a response to
the request from the server 106b. In still another embodiment, the
server 106 acquires an enumeration of applications available to the
client 102 and address information associated with a server 106
hosting an application identified by the enumeration of
applications. In yet another embodiment, the server 106 presents
the response to the request to the client 102 using a web
interface. In one embodiment, the client 102 communicates directly
with the server 106 to access the identified application. In
another embodiment, the client 102 receives application output
data, such as display data, generated by an execution of the
identified application on the server 106.
Deployed with Other Appliances.
Referring now to FIG. 1B, another embodiment of a network
environment is depicted in which the network optimization appliance
200 is deployed with one or more other appliances 205, 205'
(generally referred to as appliance 205 or second appliance 205)
such as a gateway, firewall or acceleration appliance. For example,
in one embodiment, the appliance 205 is a firewall or security
appliance while appliance 205' is a LAN acceleration device. In
some embodiments, a client 102 may communicate to a server 106 via
one or more of the first appliances 200 and one or more second
appliances 205.
One or more appliances 200 and 205 may be located at any point in
the network or network communications path between a client 102 and
a server 106. In some embodiments, a second appliance 205 may be
located on the same network 104 as the first appliance 200. In
other embodiments, the second appliance 205 may be located on a
different network 104 as the first appliance 200. In yet another
embodiment, a first appliance 200 and second appliance 205 is on
the same network, for example network 104, while the first
appliance 200' and second appliance 205' is on the same network,
such as network 104''.
In one embodiment, the second appliance 205 includes any type and
form of transport control protocol or transport later terminating
device, such as a gateway or firewall device. In one embodiment,
the appliance 205 terminates the transport control protocol by
establishing a first transport control protocol connection with the
client and a second transport control connection with the second
appliance or server. In another embodiment, the appliance 205
terminates the transport control protocol by changing, managing or
controlling the behavior of the transport control protocol
connection between the client and the server or second appliance.
For example, the appliance 205 may change, queue, forward or
transmit network packets in manner to effectively terminate the
transport control protocol connection or to act or simulate as
terminating the connection.
In some embodiments, the second appliance 205 is a performance
enhancing proxy. In one embodiment, the appliance 205 provides a
virtual private network (VPN) connection. In some embodiments, the
appliance 205 provides a Secure Socket Layer VPN (SSL VPN)
connection. In other embodiments, the appliance 205 provides an
IPsec (Internet Protocol Security) based VPN connection. In some
embodiments, the appliance 205 provides any one or more of the
following functionality: compression, acceleration, load-balancing,
switching/routing, caching, and Transport Control Protocol (TCP)
acceleration.
In one embodiment, the appliance 205 is any of the product
embodiments referred to as Access Gateway, Application Firewall,
Application Gateway, or NetScaler manufactured by Citrix Systems,
Inc. of Ft. Lauderdale, Fla. As such, in some embodiments, the
appliance 205 includes any logic, functions, rules, or operations
to perform services or functionality such as SSL VPN connectivity,
SSL offloading, switching/load balancing, Domain Name Service
resolution, LAN acceleration and an application firewall.
In some embodiments, the appliance 205 provides a SSL VPN
connection between a client 102 and a server 106. For example, a
client 102 on a first network 104 requests to establish a
connection to a server 106 on a second network 104'. In some
embodiments, the second network 104'' is not routable from the
first network 104. In other embodiments, the client 102 is on a
public network 104 and the server 106 is on a private network 104',
such as a corporate network. In one embodiment, a client agent
intercepts communications of the client 102 on the first network
104, encrypts the communications, and transmits the communications
via a first transport layer connection to the appliance 205. The
appliance 205 associates the first transport layer connection on
the first network 104 to a second transport layer connection to the
server 106 on the second network 104. The appliance 205 receives
the intercepted communication from the client agent, decrypts the
communications, and transmits the communication to the server 106
on the second network 104 via the second transport layer
connection. The second transport layer connection may be a pooled
transport layer connection. In one embodiment the appliance 205
provides an end-to-end secure transport layer connection for the
client 102 between the two networks 104, 104'
In one embodiments, the appliance 205 hosts an intranet internet
protocol or intranetIP address of the client 102 on the virtual
private network 104. The client 102 has a local network identifier,
such as an internet protocol (IP) address and/or host name on the
first network 104. When connected to the second network 104' via
the appliance 205, the appliance 205 establishes, assigns or
otherwise provides an IntranetIP, which is network identifier, such
as IP address and/or host name, for the client 102 on the second
network 104'. The appliance 205 listens for and receives on the
second or private network 104' for any communications directed
towards the client 102 using the client's established IntranetIP.
In one embodiment, the appliance 205 acts as or on behalf of the
client 102 on the second private network 104.
In some embodiment, the appliance 205 has an encryption engine
providing logic, business rules, functions or operations for
handling the processing of any security related protocol, such as
SSL or TLS, or any function related thereto. For example, the
encryption engine encrypts and decrypts network packets, or any
portion thereof, communicated via the appliance 205. The encryption
engine may also setup or establish SSL or TLS connections on behalf
of the client 102a-102n, server 106a-106n, or appliance 200, 205.
As such, the encryption engine provides offloading and acceleration
of SSL processing. In one embodiment, the encryption engine uses a
tunneling protocol to provide a virtual private network between a
client 102a-102n and a server 106a-106n. In some embodiments, the
encryption engine uses an encryption processor. In other
embodiments, the encryption engine includes executable instructions
running on an encryption processor.
In some embodiments, the appliance 205 provides one or more of the
following acceleration techniques to communications between the
client 102 and server 106: 1) compression, 2) decompression, 3)
Transmission Control Protocol pooling, 4) Transmission Control
Protocol multiplexing, 5) Transmission Control Protocol buffering,
and 6) caching. In one embodiment, the appliance 200 relieves
servers 106 of much of the processing load caused by repeatedly
opening and closing transport layers connections to clients 102 by
opening one or more transport layer connections with each server
106 and maintaining these connections to allow repeated data
accesses by clients via the Internet. This technique is referred to
herein as "connection pooling".
In some embodiments, in order to seamlessly splice communications
from a client 102 to a server 106 via a pooled transport layer
connection, the appliance 205 translates or multiplexes
communications by modifying sequence number and acknowledgment
numbers at the transport layer protocol level. This is referred to
as "connection multiplexing". In some embodiments, no application
layer protocol interaction is required. For example, in the case of
an in-bound packet (that is, a packet received from a client 102),
the source network address of the packet is changed to that of an
output port of appliance 205, and the destination network address
is changed to that of the intended server. In the case of an
outbound packet (that is, one received from a server 106), the
source network address is changed from that of the server 106 to
that of an output port of appliance 205 and the destination address
is changed from that of appliance 205 to that of the requesting
client 102. The sequence numbers and acknowledgment numbers of the
packet are also translated to sequence numbers and acknowledgement
expected by the client 102 on the appliance's 205 transport layer
connection to the client 102. In some embodiments, the packet
checksum of the transport layer protocol is recalculated to account
for these translations.
In another embodiment, the appliance 205 provides switching or
load-balancing functionality for communications between the client
102 and server 106. In some embodiments, the appliance 205
distributes traffic and directs client requests to a server 106
based on layer 4 payload or application-layer request data. In one
embodiment, although the network layer or layer 2 of the network
packet identifies a destination server 106, the appliance 205
determines the server 106 to distribute the network packet by
application information and data carried as payload of the
transport layer packet. In one embodiment, a health monitoring
program of the appliance 205 monitors the health of servers to
determine the server 106 for which to distribute a client's
request. In some embodiments, if the appliance 205 detects a server
106 is not available or has a load over a predetermined threshold,
the appliance 205 can direct or distribute client requests to
another server 106.
In some embodiments, the appliance 205 acts as a Domain Name
Service (DNS) resolver or otherwise provides resolution of a DNS
request from clients 102. In some embodiments, the appliance
intercepts' a DNS request transmitted by the client 102. In one
embodiment, the appliance 205 responds to a client's DNS request
with an IP address of or hosted by the appliance 205. In this
embodiment, the client 102 transmits network communication for the
domain name to the appliance 200. In another embodiment, the
appliance 200 responds to a client's DNS request with an IP address
of or hosted by a second appliance 200'. In some embodiments, the
appliance 205 responds to a client's DNS request with an IP address
of a server 106 determined by the appliance 200.
In yet another embodiment, the appliance 205 provides application
firewall functionality for communications between the client 102
and server 106. In one embodiment, a policy engine 295' provides
rules for detecting and blocking illegitimate requests. In some
embodiments, the application firewall protects against denial of
service (DoS) attacks. In other embodiments, the appliance inspects
the content of intercepted requests to identify and block
application-based attacks. In some embodiments, the rules/policy
engine includes one or more application firewall or security
control policies for providing protections against various classes
and types of web or Internet based vulnerabilities, such as one or
more of the following: 1) buffer overflow, 2) CGI-BIN parameter
manipulation, 3) form/hidden field manipulation, 4) forceful
browsing, 5) cookie or session poisoning, 6) broken access control
list (ACLs) or weak passwords, 7) cross-site scripting (XSS), 8)
command injection, 9) SQL injection, 10) error triggering sensitive
information leak, 11) insecure use of cryptography, 12) server
misconfiguration, 13) back doors and debug options, 14) website
defacement, 15) platform or operating systems vulnerabilities, and
16) zero-day exploits. In an embodiment, the application firewall
of the appliance provides HTML form field protection in the form of
inspecting or analyzing the network communication for one or more
of the following: 1) required fields are returned, 2) no added
field allowed, 3) read-only and hidden field enforcement, 4)
drop-down list and radio button field conformance, and 5)
form-field max-length enforcement. In some embodiments, the
application firewall of the appliance 205 ensures cookies are not
modified. In other embodiments, the appliance 205 protects against
forceful browsing by enforcing legal URLs.
In still yet other embodiments, the application firewall appliance
205 protects any confidential information contained in the network
communication. The appliance 205 may inspect or analyze any network
communication in accordance with the rules or polices of the policy
engine to identify any confidential information in any field of the
network packet. In some embodiments, the application firewall
identifies in the network communication one or more occurrences of
a credit card number, password, social security number, name,
patient code, contact information, and age. The encoded portion of
the network communication may include these occurrences or the
confidential information. Based on these occurrences, in one
embodiment, the application firewall may take a policy action on
the network communication, such as prevent transmission of the
network communication. In another embodiment, the application
firewall may rewrite, remove or otherwise mask such identified
occurrence or confidential information.
Although generally referred to as a network optimization or first
appliance 200 and a second appliance 205, the first appliance 200
and second appliance 205 may be the same type and form of
appliance. In some embodiments an appliance 205 or an appliance 200
may be any type of device or a structure capable of affecting a
data stream traversing it on the way from a client to a server or
vice versa. In one embodiment, the second appliance 205 may perform
the same functionality, or portion thereof, as the first appliance
200, and vice-versa. For example, the first appliance 200 and
second appliance 205 may both provide acceleration techniques. In
one embodiment, the first appliance may perform LAN acceleration
while the second appliance performs WAN acceleration, or
vice-versa. In another example, the first appliance 200 may also be
a transport control protocol terminating device as with the second
appliance 205. Furthermore, although appliances 200 and 205 are
shown as separate devices on the network, the appliance 200 and/or
205 could be a part of any client 102 or server 106.
Referring now to FIG. 1C, other embodiments of a network
environment for deploying the appliance 200 are depicted. In
another embodiment as depicted on the top of FIG. 1C, the appliance
200 may be deployed as a single appliance or single proxy on the
network 104. For example, the appliance 200 may be designed,
constructed or adapted to perform WAN optimization techniques
discussed herein without a second cooperating appliance 200'. In
other embodiments as depicted on the bottom of FIG. 1C, a single
appliance 200 may be deployed with one or more second appliances
205. For example, a WAN acceleration first appliance 200, such as a
Citrix WANScaler appliance, may be deployed with a LAN accelerating
or Application Firewall second appliance 205, such as a Citrix
NetScaler appliance.
Computing Device
The client 102, server 106, and appliance 200 and 205 may be
deployed as and/or executed on any type and form of computing
device, such as a computer, network device or appliance capable of
communicating on any type and form of network and performing the
operations described herein. FIGS. 1C and 1D depict block diagrams
of a computing device 100 useful for practicing an embodiment of
the client 102, server 106 or appliance 200. As shown in FIGS. 1C
and 1D, each computing device 100 may include a central processing
unit 101, and a main memory unit 122. As shown in FIG. 1C, a
computing device 100 may include a visual display device 124, a
keyboard 126 and/or a pointing device 127, such as a mouse. Each
computing device 100 may also include additional optional elements,
such as one or more input/output devices 130a-130b (generally
referred to using reference numeral 130), and a cache memory 140 in
communication with the central processing unit 101.
The central processing unit 101 is any logic circuitry that
responds to and processes instructions fetched from the main memory
unit 122. In many embodiments, the central processing unit is
provided by a microprocessor unit, such as: those manufactured by
Intel Corporation of Mountain View, Calif.; those manufactured by
Motorola Corporation of Schaumburg, Ill.; those manufactured by
Transmeta Corporation of Santa Clara, Calif.; the RS/6000
processor, those manufactured by International Business Machines of
White Plains, N.Y.; or those manufactured by Advanced Micro Devices
of Sunnyvale, Calif. The computing device 100 may be based on any
of these processors, or any other processor capable of operating as
described herein.
Main memory unit 122 may be one or more memory chips capable of
storing data and allowing any storage location to be directly
accessed by the microprocessor 101, such as Static random access
memory (SRAM), Burst SRAM or SynchBurst SRAM (BSRAM), Dynamic
random access memory (DRAM), Fast Page Mode DRAM (FPM DRAM),
Enhanced DRAM (EDRAM), Extended Data Output RAM (EDO RAM), Extended
Data Output DRAM (EDO DRAM), Burst Extended Data Output DRAM (BEDO
DRAM), Enhanced DRAM (EDRAM), synchronous DRAM (SDRAM), JEDEC SRAM,
PC100 SDRAM, Double Data Rate SDRAM (DDR SDRAM), Enhanced SDRAM
(ESDRAM), SyncLink DRAM (SLDRAM), Direct Rambus DRAM (DRDRAM), or
Ferroelectric RAM (FRAM). The main memory 122 may be based on any
of the above described memory chips, or any other available memory
chips capable of operating as described herein. In the embodiment
shown in FIG. 1C, the processor 101 communicates with main memory
122 via a system bus 150 (described in more detail below). FIG. 1C
depicts an embodiment of a computing device 100 in which the
processor communicates directly with main memory 122 via a memory
port 103. For example, in FIG. 1D the main memory 122 may be
DRDRAM.
FIG. 1D depicts an embodiment in which the main processor 101
communicates directly with cache memory 140 via a secondary bus,
sometimes referred to as a backside bus. In other embodiments, the
main processor 101 communicates with cache memory 140 using the
system bus 150. Cache memory 140 typically has a faster response
time than main memory 122 and is typically provided by SRAM, BSRAM,
or EDRAM. In the embodiment shown in FIG. 1C, the processor 101
communicates with various I/O devices 130 via a local system bus
150. Various busses may be used to connect the central processing
unit 101 to any of the I/O devices 130, including a VESA VL bus, an
ISA bus, an EISA bus, a MicroChannel Architecture (MCA) bus, a PCI
bus, a PCI-X bus, a PCI-Express bus, or a NuBus. For embodiments in
which the I/O device is a video display 124, the processor 101 may
use an Advanced Graphics Port (AGP) to communicate with the display
124. FIG. 1D depicts an embodiment of a computer 100 in which the
main processor 101 communicates directly with I/O device 130 via
HyperTransport, Rapid I/O, or InfiniBand. FIG. 1D also depicts an
embodiment in which local busses and direct communication are
mixed: the processor 101 communicates with I/O device 130 using a
local interconnect bus while communicating with I/O device 130
directly.
The computing device 100 may support any suitable installation
device 116, such as a floppy disk drive for receiving floppy disks
such as 3.5-inch, 5.25-inch disks or ZIP disks, a CD-ROM drive, a
CD-R/RW drive, a DVD-ROM drive, tape drives of various formats, USB
device, hard-drive or any other device suitable for installing
software and programs such as any client agent 120, or portion
thereof. The computing device 100 may further comprise a storage
device 128, such as one or more hard disk drives or redundant
arrays of independent disks, for storing an operating system and
other related software, and for storing application software
programs such as any program related to the client agent 120.
Optionally, any of the installation devices 116 could also be used
as the storage device 128. Additionally, the operating system and
the software can be run from a bootable medium, for example, a
bootable CD, such as KNOPPIX.RTM., a bootable CD for GNU/Linux that
is available as a GNU/Linux distribution from knoppix.net.
Furthermore, the computing device 100 may include a network
interface 118 to interface to a Local Area Network (LAN), Wide Area
Network (WAN) or the Internet through a variety of connections
including, but not limited to, standard telephone lines, LAN or WAN
links (e.g., 802.11, T1, T3, 56 kb, X.25), broadband connections
(e.g., ISDN, Frame Relay, ATM), wireless connections, or some
combination of any or all of the above. The network interface 118
may comprise a built-in network adapter, network interface card,
PCMCIA network card, card bus network adapter, wireless network
adapter, USB network adapter, modem or any other device suitable
for interfacing the computing device 100 to any type of network
capable of communication and performing the operations described
herein. A wide variety of I/O devices 130a-130n may be present in
the computing device 100. Input devices include keyboards, mice,
trackpads, trackballs, microphones, and drawing tablets. Output
devices include video displays, speakers, inkjet printers, laser
printers, and dye-sublimation printers. The I/O devices 130 may be
controlled by an I/O controller 123 as shown in FIG. 1C. The I/O
controller may control one or more I/O devices such as a keyboard
126 and a pointing device 127, e.g., a mouse or optical pen.
Furthermore, an I/O device may also provide storage 128 and/or an
installation medium 116 for the computing device 100. In still
other embodiments, the computing device 100 may provide USB
connections to receive handheld USB storage devices such as the USB
Flash Drive line of devices manufactured by Twintech Industry, Inc.
of Los Alamitos, Calif.
In some embodiments, the computing device 100 may comprise or be
connected to multiple display devices 124a-124n, which each may be
of the same or different type and/or form. As such, any of the I/O
devices 130a-130n and/or the I/O controller 123 may comprise any
type and/or form of suitable hardware, software, or combination of
hardware and software to support, enable or provide for the
connection and use of multiple display devices 124a-124n by the
computing device 100. For example, the computing device 100 may
include any type and/or form of video adapter, video card, driver,
and/or library to interface, communicate, connect or otherwise use
the display devices 124a-124n. In one embodiment, a video adapter
may comprise multiple connectors to interface to multiple display
devices 124a-124n. In other embodiments, the computing device 100
may include multiple video adapters, with each video adapter
connected to one or more of the display devices 124a-124n. In some
embodiments, any portion of the operating system of the computing
device 100 may be configured for using multiple displays 124a-124n.
In other embodiments, one or more of the display devices 124a-124n
may be provided by one or more other computing devices, such as
computing devices 100a and 100b connected to the computing device
100, for example, via a network. These embodiments may include any
type of software designed and constructed to use another computer's
display device as a second display device 124a for the computing
device 100. One ordinarily skilled in the art will recognize and
appreciate the various ways and embodiments that a computing device
100 may be configured to have multiple display devices
124a-124n.
In further embodiments, an I/O device 130 may be a bridge 170
between the system bus 150 and an external communication bus, such
as a USB bus, an Apple Desktop Bus, an RS-232 serial connection, a
SCSI bus, a FireWire bus, a FireWire 800 bus, an Ethernet bus, an
AppleTalk bus, a Gigabit Ethernet bus, an Asynchronous Transfer
Mode bus, a HIPPI bus, a Super HIPPI bus, a SerialPlus bus, a
SCI/LAMP bus, a FibreChannel bus, or a Serial Attached small
computer system interface bus.
A computing device 100 of the sort depicted in FIGS. 1C and 1D
typically operate under the control of operating systems, which
control scheduling of tasks and access to system resources. The
computing device 100 can be running any operating system such as
any of the versions of the Microsoft.RTM. Windows operating
systems, the different releases of the Unix and Linux operating
systems, any version of the Mac OS.RTM. for Macintosh computers,
any embedded operating system, any real-time operating system, any
open source operating system, any proprietary operating system, any
operating systems for mobile computing devices, or any other
operating system capable of running on the computing device and
performing the operations described herein. Typical operating
systems include: WINDOWS 3.x, WINDOWS 95, WINDOWS 98, WINDOWS 2000,
WINDOWS NT 3.51, WINDOWS NT 4.0, WINDOWS CE, and WINDOWS XP, all of
which are manufactured by Microsoft Corporation of Redmond, Wash.;
MacOS, manufactured by Apple Computer of Cupertino, Calif.; OS/2,
manufactured by International Business Machines of Armonk, N.Y.;
and Linux, a freely-available operating system distributed by
Caldera Corp. of Salt Lake City, Utah, or any type and/or form of a
Unix operating system, among others.
In other embodiments, the computing device 100 may have different
processors, operating systems, and input devices consistent with
the device. For example, in one embodiment the computer 100 is a
Treo 180, 270, 1060, 600 or 650 smart phone manufactured by Palm,
Inc. In this embodiment, the Treo smart phone is operated under the
control of the PalmOS operating system and includes a stylus input
device as well as a five-way navigator device. Moreover, the
computing device 100 can be any workstation, desktop computer,
laptop or notebook computer, server, handheld computer, mobile
telephone, any other computer, or other form of computing or
telecommunications device that is capable of communication and that
has sufficient processor power and memory capacity to perform the
operations described herein.
B. System and Appliance Architecture
Referring now to FIG. 2A, an embodiment of a system environment and
architecture of an appliance 200 for delivering and/or operating a
computing environment on a client is depicted. In some embodiments,
a server 106 includes an application delivery system 290 for
delivering a computing environment or an application and/or data
file to one or more clients 102. In brief overview, a client 102 is
in communication with a server 106 via network 104 and appliance
200. For example, the client 102 may reside in a remote office of a
company, e.g., a branch office, and the server 106 may reside at a
corporate data center. The client 102 has a client agent 120, and a
computing environment 215. The computing environment 215 may
execute or operate an application that accesses, processes or uses
a data file. The computing environment 215, application and/or data
file may be delivered via the appliance 200 and/or the server
106.
In some embodiments, the appliance 200 accelerates delivery of a
computing environment 215, or any portion thereof, to a client 102.
In one embodiment, the appliance 200 accelerates the delivery of
the computing environment 215 by the application delivery system
290. For example, the embodiments described herein may be used to
accelerate delivery of a streaming application and data file
processable by the application from a central corporate data center
to a remote user location, such as a branch office of the company.
In another embodiment, the appliance 200 accelerates transport
layer traffic between a client 102 and a server 106. In another
embodiment, the appliance 200 controls, manages, or adjusts the
transport layer protocol to accelerate delivery of the computing
environment. In some embodiments, the appliance 200 uses caching
and/or compression techniques to accelerate delivery of a computing
environment.
In some embodiments, the application delivery management system 290
provides application delivery techniques to deliver a computing
environment to a desktop of a user, remote or otherwise, based on a
plurality of execution methods and based on any authentication and
authorization policies applied via a policy engine 295. With these
techniques, a remote user may obtain a computing environment and
access to server stored applications and data files from any
network connected device 100. In one embodiment, the application
delivery system 290 may reside or execute on a server 106. In
another embodiment, the application delivery system 290 may reside
or execute on a plurality of servers 106a-106n. In some
embodiments, the application delivery system 290 may execute in a
server farm 38. In one embodiment, the server 106 executing the
application delivery system 290 may also store or provide the
application and data file. In another embodiment, a first set of
one or more servers 106 may execute the application delivery system
290, and a different server 106n may store or provide the
application and data file. In some embodiments, each of the
application delivery system 290, the application, and data file may
reside or be located on different servers. In yet another
embodiment, any portion of the application delivery system 290 may
reside, execute or be stored on or distributed to the appliance
200, or a plurality of appliances.
The client 102 may include a computing environment 215 for
executing an application that uses or processes a data file. The
client 102 via networks 104, 104' and appliance 200 may request an
application and data file from the server 106. In one embodiment,
the appliance 200 may forward a request from the client 102 to the
server 106. For example, the client 102 may not have the
application and data file stored or accessible locally. In response
to the request, the application delivery system 290 and/or server
106 may deliver the application and data file to the client 102.
For example, in one embodiment, the server 106 may transmit the
application as an application stream to operate in computing
environment 215 on client 102.
In some embodiments, the application delivery system 290 comprises
any portion of the Citrix Access Suite.TM. by Citrix Systems, Inc.,
such as the MetaFrame or Citrix Presentation Server.TM. and/or any
of the Microsoft.RTM. Windows Terminal Services manufactured by the
Microsoft Corporation. In one embodiment, the application delivery
system 290 may deliver one or more applications to clients 102 or
users via a remote-display protocol or otherwise via remote-based
or server-based computing. In another embodiment, the application
delivery system 290 may deliver one or more applications to clients
or users via steaming of the application.
In one embodiment, the application delivery system 290 includes a
policy engine 295 for controlling and managing the access to,
selection of application execution methods and the delivery of
applications. In some embodiments, the policy engine 295 determines
the one or more applications a user or client 102 may access. In
another embodiment, the policy engine 295 determines how the
application should be delivered to the user or client 102, e.g.,
the method of execution. In some embodiments, the application
delivery system 290 provides a plurality of delivery techniques
from which to select a method of application execution, such as a
server-based computing, streaming or delivering the application
locally to the client 120 for local execution.
In one embodiment, a client 102 requests execution of an
application program and the application delivery system 290
comprising a server 106 selects a method of executing the
application program. In some embodiments, the server 106 receives
credentials from the client 102. In another embodiment, the server
106 receives a request for an enumeration of available applications
from the client 102. In one embodiment, in response to the request
or receipt of credentials, the application delivery system 290
enumerates a plurality of application programs available to the
client 102. The application delivery system 290 receives a request
to execute an enumerated application. The application delivery
system 290 selects one of a predetermined number of methods for
executing the enumerated application, for example, responsive to a
policy of a policy engine. The application delivery system 290 may
select a method of execution of the application enabling the client
102 to receive application-output data generated by execution of
the application program on a server 106. The application delivery
system 290 may select a method of execution of the application
enabling the client or local machine 102 to execute the application
program locally after retrieving a plurality of application files
comprising the application. In yet another embodiment, the
application delivery system 290 may select a method of execution of
the application to stream the application via the network 104 to
the client 102.
A client 102 may execute, operate or otherwise provide an
application, which can be any type and/or form of software,
program, or executable instructions such as any type and/or form of
web browser, web-based client, client-server application, a
thin-client computing client, an ActiveX control, or a Java applet,
or any other type and/or form of executable instructions capable of
executing on client 102. In some embodiments, the application may
be a server-based or a remote-based application executed on behalf
of the client 102 on a server 106. In one embodiment the server 106
may display output to the client 102 using any thin-client or
remote-display protocol, such as the Independent Computing
Architecture (ICA) protocol manufactured by Citrix Systems, Inc. of
Ft. Lauderdale, Fla. or the Remote Desktop Protocol (RDP)
manufactured by the Microsoft Corporation of Redmond, Wash. The
application can use any type of protocol and it can be, for
example, an HTTP client, an FTP client, an Oscar client, or a
Telnet client. In other embodiments, the application comprises any
type of software related to VoIP communications, such as a soft IP
telephone. In further embodiments, the application comprises any
application related to real-time data communications, such as
applications for streaming video and/or audio.
In some embodiments, the server 106 or a server farm 38 may be
running one or more applications, such as an application providing
a thin-client computing or remote display presentation application.
In one embodiment, the server 106 or server farm 38 executes as an
application, any portion of the Citrix Access Suite.TM. by Citrix
Systems, Inc., such as the MetaFrame or Citrix Presentation
Server.TM., and/or any of the Microsoft.RTM. Windows Terminal
Services manufactured by the Microsoft Corporation. In one
embodiment, the application is an ICA client, developed by Citrix
Systems, Inc. of Fort Lauderdale, Fla. In other embodiments, the
application includes a Remote Desktop (RDP) client, developed by
Microsoft Corporation of Redmond, Wash. Also, the server 106 may
run an application, which for example, may be an application server
providing email services such as Microsoft Exchange manufactured by
the Microsoft Corporation of Redmond, Wash., a web or Internet
server, or a desktop sharing server, or a collaboration server. In
some embodiments, any of the applications may comprise any type of
hosted service or products, such as GoToMeeting.TM. provided by
Citrix Online Division, Inc. of Santa Barbara, Calif., WebEx.TM.
provided by WebEx, Inc. of Santa Clara, Calif., or Microsoft Office
Live Meeting provided by Microsoft Corporation of Redmond,
Wash.
Example Appliance Architecture
FIG. 2A also illustrates an example embodiment of the appliance
200. The architecture of the appliance 200 in FIG. 2A is provided
by way of illustration only and is not intended to be limiting in
any manner. The appliance 200 may include any type and form of
computing device 100, such as any element or portion described in
conjunction with FIGS. 1D and 1E above. In brief overview, the
appliance 200 has one or more network ports 266A-226N and one or
more networks stacks 267A-267N for receiving and/or transmitting
communications via networks 104. The appliance 200 also has a
network optimization engine 250 for optimizing, accelerating or
otherwise improving the performance, operation, or quality of any
network traffic or communications traversing the appliance 200.
The appliance 200 includes or is under the control of an operating
system. The operating system of the appliance 200 may be any type
and/or form of Unix operating system although the disclosure is not
so limited. As such, the appliance 200 can be running any operating
system such as any of the versions of the Microsoft.RTM. Windows
operating systems, the different releases of the Unix and Linux
operating systems, any version of the Mac OS.RTM. for Macintosh
computers, any embedded operating system, any network operating
system, any real-time operating system, any open source operating
system, any proprietary operating system, any operating systems for
mobile computing devices or network devices, or any other operating
system capable of running on the appliance 200 and performing the
operations described herein.
The operating system of appliance 200 allocates, manages, or
otherwise segregates the available system memory into what is
referred to as kernel or system space, and user or application
space. The kernel space is typically reserved for running the
kernel, including any device drivers, kernel extensions or other
kernel related software. As known to those skilled in the art, the
kernel is the core of the operating system, and provides access,
control, and management of resources and hardware-related elements
of the appliance 200. In accordance with an embodiment of the
appliance 200, the kernel space also includes a number of network
services or processes working in conjunction with the network
optimization engine 250, or any portion thereof. Additionally, the
embodiment of the kernel will depend on the embodiment of the
operating system installed, configured, or otherwise used by the
device 200. In contrast to kernel space, user space is the memory
area or portion of the operating system used by user mode
applications or programs otherwise running in user mode. A user
mode application may not access kernel space directly and uses
service calls in order to access kernel services. The operating
system uses the user or application space for executing or running
applications and provisioning of user level programs, services,
processes and/or tasks.
The appliance 200 has one or more network ports 266 for
transmitting and receiving data over a network 104. The network
port 266 provides a physical and/or logical interface between the
computing device and a network 104 or another device 100 for
transmitting and receiving network communications. The type and
form of network port 266 depends on the type and form of network
and type of medium for connecting to the network. Furthermore, any
software of, provisioned for or used by the network port 266 and
network stack 267 may run in either kernel space or user space.
In one embodiment, the appliance 200 has one network stack 267,
such as a TCP/IP based stack, for communicating on a network 105,
such with the client 102 and/or the server 106. In one embodiment,
the network stack 267 is used to communicate with a first network,
such as network 104, and also with a second network 104'. In
another embodiment, the appliance 200 has two or more network
stacks, such as first network stack 267A and a second network stack
267N. The first network stack 267A may be used in conjunction with
a first port 266A to communicate on a first network 104. The second
network stack 267N may be used in conjunction with a second port
266N to communicate on a second network 104'. In one embodiment,
the network stack(s) 267 has one or more buffers for queuing one or
more network packets for transmission by the appliance 200.
The network stack 267 includes any type and form of software, or
hardware, or any combinations thereof, for providing connectivity
to and communications with a network. In one embodiment, the
network stack 267 includes a software implementation for a network
protocol suite. The network stack 267 may have one or more network
layers, such as any networks layers of the Open Systems
Interconnection (OSI) communications model as those skilled in the
art recognize and appreciate. As such, the network stack 267 may
have any type and form of protocols for any of the following layers
of the OSI model: 1) physical link layer, 2) data link layer, 3)
network layer, 4) transport layer, 5) session layer, 6)
presentation layer, and 7) application layer. In one embodiment,
the network stack 267 includes a transport control protocol (TCP)
over the network layer protocol of the internet protocol (IP),
generally referred to as TCP/IP. In some embodiments, the TCP/IP
protocol may be carried over the Ethernet protocol, which may
comprise any of the family of IEEE wide-area-network (WAN) or
local-area-network (LAN) protocols, such as those protocols covered
by the IEEE 802.3. In some embodiments, the network stack 267 has
any type and form of a wireless protocol, such as IEEE 802.11
and/or mobile internet protocol.
In view of a TCP/IP based network, any TCP/IP based protocol may be
used, including Messaging Application Programming Interface (MAPI)
(email), File Transfer Protocol (FTP), HyperText Transfer Protocol
(HTTP), Common Internet File System (CIFS) protocol (file
transfer), Independent Computing Architecture (ICA) protocol,
Remote Desktop Protocol (RDP), Wireless Application Protocol (WAP),
Mobile IP protocol, and Voice Over IP (VoIP) protocol. In another
embodiment, the network stack 267 comprises any type and form of
transport control protocol, such as a modified transport control
protocol, for example a Transaction TCP (T/TCP), TCP with selection
acknowledgements (TCP-SACK), TCP with large windows (TCP-LW), a
congestion prediction protocol such as the TCP-Vegas protocol, and
a TCP spoofing protocol. In other embodiments, any type and form of
user datagram protocol (UDP), such as UDP over IP, may be used by
the network stack 267, such as for voice communications or
real-time data communications.
Furthermore, the network stack 267 may include one or more network
drivers supporting the one or more layers, such as a TCP driver or
a network layer driver. The network drivers may be included as part
of the operating system of the computing device 100 or as part of
any network interface cards or other network access components of
the computing device 100. In some embodiments, any of the network
drivers of the network stack 267 may be customized, modified or
adapted to provide a custom or modified portion of the network
stack 267 in support of any of the techniques described herein.
In one embodiment, the appliance 200 provides for or maintains a
transport layer connection between a client 102 and server 106
using a single network stack 267. In some embodiments, the
appliance 200 effectively terminates the transport layer connection
by changing, managing or controlling the behavior of the transport
control protocol connection between the client and the server. In
these embodiments, the appliance 200 may use a single network stack
267. In other embodiments, the appliance 200 terminates a first
transport layer connection, such as a TCP connection of a client
102, and establishes a second transport layer connection to a
server 106 for use by or on behalf of the client 102, e.g., the
second transport layer connection is terminated at the appliance
200 and the server 106. The first and second transport layer
connections may be established via a single network stack 267. In
other embodiments, the appliance 200 may use multiple network
stacks, for example 267A and 267N. In these embodiments, the first
transport layer connection may be established or terminated at one
network stack 267A, and the second transport layer connection may
be established or terminated on the second network stack 267N. For
example, one network stack may be for receiving and transmitting
network packets on a first network, and another network stack for
receiving and transmitting network packets on a second network.
As shown in FIG. 2A, the network optimization engine 250 includes
one or more of the following elements, components or modules:
network packet processing engine 240, LAN/WAN detector 210, flow
controller 220, QoS engine 236, protocol accelerator 234,
compression engine 238, cache manager 232 and policy engine 295'.
The network optimization engine 250, or any portion thereof, may
include software, hardware or any combination of software and
hardware. Furthermore, any software of, provisioned for or used by
the network optimization engine 250 may run in either kernel space
or user space. For example, in one embodiment, the network
optimization engine 250 may run in kernel space. In another
embodiment, the network optimization engine 250 may run in user
space. In yet another embodiment, a first portion of the network
optimization engine 250 runs in kernel space while a second portion
of the network optimization engine 250 runs in user space.
Network Packet Processing Engine
The network packet engine 240, also generally referred to as a
packet processing engine or packet engine, is responsible for
controlling and managing the processing of packets received and
transmitted by appliance 200 via network ports 266 and network
stack(s) 267. The network packet engine 240 may operate at any
layer of the network stack 267. In one embodiment, the network
packet engine 240 operates at layer 2 or layer 3 of the network
stack 267. In some embodiments, the packet engine 240 intercepts or
otherwise receives packets at the network layer, such as the IP
layer in a TCP/IP embodiment. In another embodiment, the packet
engine 240 operates at layer 4 of the network stack 267. For
example, in some embodiments, the packet engine 240 intercepts or
otherwise receives packets at the transport layer, such as
intercepting packets as the TCP layer in a TCP/IP embodiment. In
other embodiments, the packet engine 240 operates at any session or
application layer above layer 4. For example, in one embodiment,
the packet engine 240 intercepts or otherwise receives network
packets above the transport layer protocol layer, such as the
payload of a TCP packet in a TCP embodiment.
The packet engine 240 may include a buffer for queuing one or more
network packets during processing, such as for receipt of a network
packet or transmission of a network packet. Additionally, the
packet engine 240 is in communication with one or more network
stacks 267 to send and receive network packets via network ports
266. The packet engine 240 may include a packet processing timer.
In one embodiment, the packet processing timer provides one or more
time intervals to trigger the processing of incoming, i.e.,
received, or outgoing, i.e., transmitted, network packets. In some
embodiments, the packet engine 240 processes network packets
responsive to the timer. The packet processing timer provides any
type and form of signal to the packet engine 240 to notify,
trigger, or communicate a time related event, interval or
occurrence. In many embodiments, the packet processing timer
operates in the order of milliseconds, such as for example 100 ms,
50 ms, 25 ms, 10 ms, 5 ms or 1 ms.
During operations, the packet engine 240 may be interfaced,
integrated or be in communication with any portion of the network
optimization engine 250, such as the LAN/WAN detector 210, flow
controller 220, QoS engine 236, protocol accelerator 234,
compression engine 238, cache manager 232 and/or policy engine
295'. As such, any of the logic, functions, or operations of the
LAN/WAN detector 210, flow controller 220, QoS engine 236, protocol
accelerator 234, compression engine 238, cache manager 232 and
policy engine 295' may be performed responsive to the packet
processing timer and/or the packet engine 240. In some embodiments,
any of the logic, functions, or operations of the encryption engine
234, cache manager 232, policy engine 236 and multi-protocol
compression logic 238 may be performed at the granularity of time
intervals provided via the packet processing timer, for example, at
a time interval of less than or equal to 10 ms. For example, in one
embodiment, the cache manager 232 may perform expiration of any
cached objects responsive to the integrated packet engine 240
and/or the packet processing timer 242. In another embodiment, the
expiry or invalidation time of a cached object can be set to the
same order of granularity as the time interval of the packet
processing timer, such as at every 10 ms.
Cache Manager
The cache manager 232 may include software, hardware or any
combination of software and hardware to store data, information and
objects to a cache in memory or storage, provide cache access, and
control and manage the cache. The data, objects or content
processed and stored by the cache manager 232 may include data in
any format, such as a markup language, or any type of data
communicated via any protocol. In some embodiments, the cache
manager 232 duplicates original data stored elsewhere or data
previously computed, generated or transmitted, in which the
original data may require longer access time to fetch, compute or
otherwise obtain relative to reading a cache memory or storage
element. Once the data is stored in the cache, future use can be
made by accessing the cached copy rather than re-fetching or
re-computing the original data, thereby reducing the access time.
In some embodiments, the cache may comprise a data object in memory
of the appliance 200. In another embodiment, the cache may comprise
any type and form of storage element of the appliance 200, such as
a portion of a hard disk. In some embodiments, the processing unit
of the device may provide cache memory for use by the cache manager
232. In yet further embodiments, the cache manager 232 may use any
portion and combination of memory, storage, or the processing unit
for caching data, objects, and other content.
Furthermore, the cache manager 232 includes any logic, functions,
rules, or operations to perform any caching techniques of the
appliance 200. In some embodiments, the cache manager 232 may
operate as an application, library, program, service, process,
thread or task. In some embodiments, the cache manager 232 can
comprise any type of general purpose processor (GPP), or any other
type of integrated circuit, such as a Field Programmable Gate Array
(FPGA), Programmable Logic Device (PLD), or Application Specific
Integrated Circuit (ASIC).
Policy Engine
The policy engine 295' includes any logic, function or operations
for providing and applying one or more policies or rules to the
function, operation or configuration of any portion of the
appliance 200. The policy engine 295' may include, for example, an
intelligent statistical engine or other programmable
application(s). In one embodiment, the policy engine 295 provides a
configuration mechanism to allow a user to identify, specify,
define or configure a policy for the network optimization engine
250, or any portion thereof. For example, the policy engine 295 may
provide policies for what data to cache, when to cache the data,
for whom to cache the data, when to expire an object in cache or
refresh the cache. In other embodiments, the policy engine 236 may
include any logic, rules, functions or operations to determine and
provide access, control and management of objects, data or content
being cached by the appliance 200 in addition to access, control
and management of security, network traffic, network access,
compression or any other function or operation performed by the
appliance 200.
In some embodiments, the policy engine 295' provides and applies
one or more policies based on any one or more of the following: a
user, identification of the client, identification of the server,
the type of connection, the time of the connection, the type of
network, or the contents of the network traffic. In one embodiment,
the policy engine 295' provides and applies a policy based on any
field or header at any protocol layer of a network packet. In
another embodiment, the policy engine 295' provides and applies a
policy based on any payload of a network packet. For example, in
one embodiment, the policy engine 295' applies a policy based on
identifying a certain portion of content of an application layer
protocol carried as a payload of a transport layer packet. In
another example, the policy engine 295' applies a policy based on
any information identified by a client, server or user certificate.
In yet another embodiment, the policy engine 295' applies a policy
based on any attributes or characteristics obtained about a client
102, such as via any type and form of endpoint detection (see for
example the collection agent of the client agent discussed
below).
In one embodiment, the policy engine 295' works in conjunction or
cooperation with the policy engine 295 of the application delivery
system 290. In some embodiments, the policy engine 295' is a
distributed portion of the policy engine 295 of the application
delivery system 290. In another embodiment, the policy engine 295
of the application delivery system 290 is deployed on or executed
on the appliance 200. In some embodiments, the policy engines 295,
295' both operate on the appliance 200. In yet another embodiment,
the policy engine 295', or a portion thereof, of the appliance 200
operates on a server 106.
Multi-Protocol and Multi-Layer Compression Engine
The compression engine 238 includes any logic, business rules,
function or operations for compressing one or more protocols of a
network packet, such as any of the protocols used by the network
stack 267 of the appliance 200. The compression engine 238 may also
be referred to as a multi-protocol compression engine 238 in that
it may be designed, constructed or capable of compressing a
plurality of protocols. In one embodiment, the compression engine
238 applies context insensitive compression, which is compression
applied to data without knowledge of the type of data. In another
embodiment, the compression engine 238 applies context-sensitive
compression. In this embodiment, the compression engine 238
utilizes knowledge of the data type to select a specific
compression algorithm from a suite of suitable algorithms. In some
embodiments, knowledge of the specific protocol is used to perform
context-sensitive compression. In one embodiment, the appliance 200
or compression engine 238 can use port numbers (e.g., well-known
ports), as well as data from the connection itself to determine the
appropriate compression algorithm to use. Some protocols use only a
single type of data, requiring only a single compression algorithm
that can be selected when the connection is established. Other
protocols contain different types of data at different times. For
example, POP, IMAP, SMTP, and HTTP all move files of arbitrary
types interspersed with other protocol data.
In one embodiment, the compression engine 238 uses a delta-type
compression algorithm. In another embodiment, the compression
engine 238 uses first site compression as well as searching for
repeated patterns among data stored in cache, memory or disk. In
some embodiments, the compression engine 238 uses a lossless
compression algorithm. In other embodiments, the compression engine
uses a lossy compression algorithm. In some cases, knowledge of the
data type and, sometimes, permission from the user are required to
use a lossy compression algorithm. Compression is not limited to
the protocol payload. The control fields of the protocol itself may
be compressed. In some embodiments, the compression engine 238 uses
a different algorithm than that used for the payload.
In some embodiments, the compression engine 238 compresses at one
or more layers of the network stack 267. In one embodiment, the
compression engine 238 compresses at a transport layer protocol. In
another embodiment, the compression engine 238 compresses at an
application layer protocol. In some embodiments, the compression
engine 238 compresses at a layer 2-4 protocol. In other
embodiments, the compression engine 238 compresses at a layer 5-7
protocol. In yet another embodiment, the compression engine
compresses a transport layer protocol and an application layer
protocol. In some embodiments, the compression engine 238
compresses a layer 2-4 protocol and a layer 5-7 protocol.
In some embodiments, the compression engine 238 uses memory-based
compression, cache-based compression or disk-based compression or
any combination thereof. As such, the compression engine 238 may be
referred to as a multi-layer compression engine. In one embodiment,
the compression engine 238 uses a history of data stored in memory,
such as RAM. In another embodiment, the compression engine 238 uses
a history of data stored in a cache, such as L2 cache of the
processor. In other embodiments, the compression engine 238 uses a
history of data stored to a disk or storage location. In some
embodiments, the compression engine 238 uses a hierarchy of
cache-based, memory-based and disk-based data history. The
compression engine 238 may first use the cache-based data to
determine one or more data matches for compression, and then may
check the memory-based data to determine one or more data matches
for compression. In another case, the compression engine 238 may
check disk storage for data matches for compression after checking
either the cache-based and/or memory-based data history.
In one embodiment, multi-protocol compression engine 238 compresses
bi-directionally between clients 102a-102n and servers 106a-106n
any TCP/IP based protocol, including Messaging Application
Programming Interface (MAPI) (email), File Transfer Protocol (FTP),
HyperText Transfer Protocol (HTTP), Common Internet File System
(CIFS) protocol (file transfer), Independent Computing Architecture
(ICA) protocol, Remote Desktop Protocol (RDP), Wireless Application
Protocol (WAP), Mobile IP protocol, and Voice Over IP (VoIP)
protocol. In other embodiments, multi-protocol compression engine
238 provides compression of HyperText Markup Language (HTML) based
protocols and in some embodiments, provides compression of any
markup languages, such as the Extensible Markup Language (XML). In
one embodiment, the multi-protocol compression engine 238 provides
compression of any high-performance protocol, such as any protocol
designed for appliance 200 to appliance 200 communications. In
another embodiment, the multi-protocol compression engine 238
compresses any payload of or any communication using a modified
transport control protocol, such as Transaction TCP (T/TCP), TCP
with selection acknowledgements (TCP-SACK), TCP with large windows
(TCP-LW), a congestion prediction protocol such as the TCP-Vegas
protocol, and a TCP spoofing protocol.
As such, the multi-protocol compression engine 238 accelerates
performance for users accessing applications via desktop clients,
e.g., Microsoft Outlook and non-Web thin clients, such as any
client launched by popular enterprise applications like Oracle, SAP
and Siebel, and even mobile clients, such as the Pocket PC. In some
embodiments, the multi-protocol compression engine by integrating
with packet processing engine 240 accessing the network stack 267
is able to compress any of the protocols carried by a transport
layer protocol, such as any application layer protocol.
LAN/WAN Detector
The LAN/WAN detector 238 includes any logic, business rules,
function or operations for automatically detecting a slow side
connection (e.g., a wide area network (WAN) connection such as an
Intranet) and associated port 267, and a fast side connection
(e.g., a local area network (LAN) connection) and an associated
port 267. In some embodiments, the LAN/WAN detector 238 monitors
network traffic on the network ports 267 of the appliance 200 to
detect a synchronization packet, sometimes referred to as a
"tagged" network packet. The synchronization packet identifies a
type or speed of the network traffic. In one embodiment, the
synchronization packet identifies a WAN speed or WAN type
connection. The LAN/WAN detector 238 also identifies receipt of an
acknowledgement packet to a tagged synchronization packet and on
which port it is received. The appliance 200 then configures itself
to operate the identified port on which the tagged synchronization
packet arrived so that the speed on that port is set to be the
speed associated with the network connected to that port. The other
port is then set to the speed associated with the network connected
to that port.
For ease of discussion herein, reference to "fast" side will be
made with respect to connection with a wide area network (WAN),
e.g., the Internet, and operating at a network speed of the WAN.
Likewise, reference to "slow" side will be made with respect to
connection with a local area network (LAN) and operating at a
network speed the LAN. However, it is noted that "fast" and "slow"
sides in a network can change on a per-connection basis and are
relative terms to the speed of the network connections or to the
type of network topology. Such configurations are useful in complex
network topologies, where a network is "fast" or "slow" only when
compared to adjacent networks and not in any absolute sense.
In one embodiment, the LAN/WAN detector 238 may be used to allow
for auto-discovery by an appliance 200 of a network to which it
connects. In another embodiment, the LAN/WAN detector 238 may be
used to detect the existence or presence of a second appliance 200'
deployed in the network 104. For example, an auto-discovery
mechanism in operation in accordance with FIG. 1A functions as
follows: appliance 200 and 200' are placed in line with the
connection linking client 102 and server 106. The appliances 200
and 200' are at the ends of a low-speed link, e.g., Internet,
connecting two LANs. In one example embodiment, appliances 200 and
200' each include two ports--one to connect with the "lower" speed
link and the other to connect with a "higher" speed link, e.g., a
LAN. Any packet arriving at one port is copied to the other port.
Thus, appliance 200 and 200' are each configured to function as a
bridge between the two networks 104.
When an end node, such as the client 102, opens a new TCP
connection with another end node, such as the server 106, the
client 102 sends a TCP packet with a synchronization (SYN) header
bit set, or a SYN packet, to the server 106. In the present
example, client 102 opens a transport layer connection to server
106. When the SYN packet passes through appliance 200, the
appliance 200 inserts, attaches or otherwise provides a
characteristic TCP header option to the packet, which announces its
presence. If the packet passes through a second appliance, in this
example appliance 200' the second appliance notes the header option
on the SYN packet. The server 106 responds to the SYN packet with a
synchronization acknowledgment (SYN-ACK) packet. When the SYN-ACK
packet passes through appliance 200', a TCP header option is tagged
(e.g., attached, inserted or added) to the SYN-ACK packet to
announce appliance 200' presence to appliance 200. When appliance
200 receives this packet, both appliances 200, 200' are now aware
of each other and the connection can be appropriately
accelerated.
Further to the operations of the LAN/WAN detector 238, a method or
process for detecting "fast" and "slow" sides of a network using a
SYN packet is described. During a transport layer connection
establishment between a client 102 and a server 106, the appliance
200 via the LAN/WAN detector 238 determines whether the SYN packet
is tagged with an acknowledgement (ACK). If it is tagged, the
appliance 200 identifies or configures the port receiving the
tagged SYN packet (SYN-ACK) as the "slow" side. In one embodiment,
the appliance 200 optionally removes the ACK tag from the packet
before copying the packet to the other port. If the LAN/WAN
detector 238 determines that the packet is not tagged, the
appliance 200 identifies or configure the port receiving the
untagged packet as the "fast" side. The appliance 200 then tags the
SYN packet with an ACK and copies the packet to the other port.
In another embodiment, the LAN/WAN detector 238 detects fast and
slow sides of a network using a SYN-ACK packet. The appliance 200
via the LAN/WAN detector 238 determines whether the SYN-ACK packet
is tagged with an acknowledgement (ACK). If it is tagged, the
appliance 200 identifies or configures the port receiving the
tagged SYN packet (SYN-ACK) as the "slow" side. In one embodiment,
the appliance 200 optionally removes the ACK tag from the packet
before copying the packet to the other port. If the LAN/WAN
detector 238 determines that the packet is not tagged, the
appliance 200 identifies or configures the port receiving the
untagged packet as the "fast" side. The LAN/WAN detector 238
determines whether the SYN packet was tagged. If the SYN packet was
not tagged, the appliance 200 copied the packet to the other port.
If the SYN packet was tagged, the appliance tags the SYN-ACK packet
before copying it to the other port.
The appliance 200, 200' may add, insert, modify, attach or
otherwise provide any information or data in the TCP option header
to provide any information, data or characteristics about the
network connection, network traffic flow, or the configuration or
operation of the appliance 200. In this manner, not only does an
appliance 200 announce its presence to another appliance 200' or
tag a higher or lower speed connection, the appliance 200 provides
additional information and data via the TCP option headers about
the appliance or the connection. The TCP option header information
may be useful to or used by an appliance in controlling, managing,
optimizing, acceleration or improving the network traffic flow
traversing the appliance 200, or to otherwise configure itself or
operation of a network port.
Although generally described in conjunction with detecting speeds
of network connections or the presence of appliances, the LAN/WAN
detector 238 can be used for applying any type of function, logic
or operation of the appliance 200 to a port, connection or flow of
network traffic. In particular, automated assignment of ports can
occur whenever a device performs different functions on different
ports, where the assignment of a port to a task can be made during
the unit's operation, and/or the nature of the network segment on
each port is discoverable by the appliance 200.
Flow Control
The flow controller 220 includes any logic, business rules, logical
rules, functions or operations for optimizing, accelerating or
otherwise improving the performance, operation or quality of
service of transport layer communications of network packets or the
delivery of packets at the transport layer. A flow controller, also
sometimes referred to as a flow control module, regulates, manages
and controls data transfer rates. In some embodiments, the flow
controller 220 is deployed at or connected at a bandwidth
bottleneck in the network 104. In one embodiment, the flow
controller 220 effectively regulates, manages and controls
bandwidth usage or utilization. In other embodiments, the flow
control modules may also be deployed at points on the network of
latency transitions (low latency to high latency) and on links with
media losses (such as wireless or satellite links).
In some embodiments, a flow controller 220 may include a
receiver-side flow control module for controlling the rate of
receipt of network transmissions and a sender-side flow control
module for the controlling the rate of transmissions of network
packets. In other embodiments, a first flow controller 220 includes
a receiver-side flow control module and a second flow controller
220' includes a sender-side flow control module. In some
embodiments, a first flow controller 220 is deployed on a first
appliance 200 and a second flow controller 220' is deployed on a
second appliance 200'. As such, in some embodiments, a first
appliance 200 controls the flow of data on the receiver side and a
second appliance 200' controls the data flow from the sender side.
In yet another embodiment, a single appliance 200 includes flow
control for both the receiver-side and sender-side of network
communications traversing the appliance 200.
In one embodiment, a flow control module 220 is configured to allow
bandwidth at the bottleneck to be more fully utilized, and in some
embodiments, not overutilized. In some embodiments, the flow
control module 220 transparently buffers (or rebuffers data already
buffered by, for example, the sender) network sessions that pass
between nodes having associated flow control modules 220. When a
session passes through two or more flow control modules 220, one or
more of the flow control modules controls a rate of the
session(s).
In one embodiment, the flow control module 200 is configured with
predetermined data relating to bottleneck bandwidth. In another
embodiment, the flow control module 220 may be configured to detect
the bottleneck bandwidth or data associated therewith. Unlike
conventional network protocols such as TCP, a receiver-side flow
control module 220 controls the data transmission rate. The
receiver-side flow control module controls 220 the sender-side flow
control module, e.g., 220, data transmission rate by forwarding
transmission rate limits to the sender-side flow control module
220. In one embodiment, the receiver-side flow control module 220
piggybacks these transmission rate limits on acknowledgement (ACK)
packets (or signals) sent to the sender, e.g., client 102, by the
receiver, e.g., server 106. The receiver-side flow control module
220 does this in response to rate control requests that are sent by
the sender side flow control module 220'. The requests from the
sender-side flow control module 220' may be "piggybacked" on data
packets sent by the sender 106.
In some embodiments, the flow controller 220 manipulates, adjusts,
simulates, changes, improves or otherwise adapts the behavior of
the transport layer protocol or any other layer protocol to provide
improved performance or operations of delivery, data rates and/or
bandwidth utilization of the transport layer. The flow controller
220 may implement a plurality of data flow control techniques at
the transport layer, including but not limited to 1)
pre-acknowledgements, 2) window virtualization, 3) recongestion
techniques, 3) local retransmission techniques, 4) wavefront
detection and disambiguation, 5) transport control protocol
selective acknowledgements, 6) transaction boundary detection
techniques and 7) repacketization.
Although a sender may be generally described herein as a client 102
and a receiver as a server 106, a sender may be any end point such
as a server 106 or any computing device 100 on the network 104.
Likewise, a receiver may be a client 102 or any other computing
device on the network 104.
Pre-Acknowledgements
In brief overview of a pre-acknowledgement flow control technique,
the flow controller 220, in some embodiments, handles the
acknowledgements and retransmits for a sender, effectively
terminating the sender's connection with the downstream portion of
a network connection. In reference to FIG. 1B, one possible
deployment of an appliance 200 into a network architecture to
implement this feature is depicted. In this example environment, a
sending computer or client 102 transmits data on network 104, for
example, via a switch, which determines that the data is destined
for VPN appliance 205. Because of the chosen network topology, all
data destined for VPN appliance 205 traverses appliance 200, so the
appliance 200 can apply any necessary algorithms to this data.
Continuing further with the example, the client 102 transmits a
packet, which is received by the appliance 200. When the appliance
200 receives the packet, which is transmitted from the client 102
to a recipient via the VPN appliance 205 the appliance 200 retains
a copy of the packet and forwards the packet downstream to the VPN
appliance 205. The appliance 200 then generates an acknowledgement
packet (ACK) and sends the ACK packet back to the client 102 or
sending endpoint. This ACK, a pre-acknowledgment, causes the sender
102 to believe that the packet has been delivered successfully,
freeing the sender's resources for subsequent processing. The
appliance 200 retains the copy of the packet data in the event that
a retransmission of the packet is required, so that the sender 102
does not have to handle retransmissions of the data. This early
generation of acknowledgements may be called "preacking."
If a retransmission of the packet is required, the appliance 200
retransmits the packet to the sender. The appliance 200 may
determine whether retransmission is required as a sender would in a
traditional system, for example, determining that a packet is lost
if an acknowledgement has not been received for the packet after a
predetermined amount of time. To this end, the appliance 200
monitors acknowledgements generated by the receiving endpoint,
e.g., server 106 (or any other downstream network entity) so that
it can determine whether the packet has been successfully delivered
or needs to be retransmitted. If the appliance 200 determines that
the packet has been successfully delivered, the appliance 200 is
free to discard the saved packet data. The appliance 200 may also
inhibit forwarding acknowledgements for packets that have already
been received by the sending endpoint.
In the embodiment described above, the appliance 200 via the flow
controller 220 controls the sender 102 through the delivery of
pre-acknowledgements, also referred to as "preacks", as though the
appliance 200 was a receiving endpoint itself. Since the appliance
200 is not an endpoint and does not actually consume the data, the
appliance 200 includes a mechanism for providing overflow control
to the sending endpoint. Without overflow control, the appliance
200 could run out of memory because the appliance 200 stores
packets that have been preacked to the sending endpoint but not yet
acknowledged as received by the receiving endpoint. Therefore, in a
situation in which the sender 102 transmits packets to the
appliance 200 faster than the appliance 200 can forward the packets
downstream, the memory available in the appliance 200 to store
unacknowledged packet data can quickly fill. A mechanism for
overflow control allows the appliance 200 to control transmission
of the packets from the sender 102 to avoid this problem.
In one embodiment, the appliance 200 or flow controller 220
includes an inherent "self-clocking" overflow control mechanism.
This self-clocking is due to the order in which the appliance 200
may be designed to transmit packets downstream and send ACKs to the
sender 102 or 106. In some embodiments, the appliance 200 does not
preack the packet until after it transmits the packet downstream.
In this way, the sender 102 will receive the ACKs at the rate at
which the appliance 200 is able to transmit packets rather than the
rate at which the appliance 200 receives packets from the sender
100. This helps to regulate the transmission of packets from a
sender 102.
Window Virtualization
Another overflow control mechanism that the appliance 200 may
implement is to use the TCP window size parameter, which tells a
sender how much buffer the receiver is permitting the sender to
fill up. A nonzero window size (e.g., a size of at least one
Maximum Segment Size (MSS)) in a preack permits the sending
endpoint to continue to deliver data to the appliance, whereas a
zero window size inhibits further data transmission. Accordingly,
the appliance 200 may regulate the flow of packets from the sender,
for example when the appliance's 200 buffer is becoming full, by
appropriately setting the TCP window size in each preack.
Another technique to reduce this additional overhead is to apply
hysteresis. When the appliance 200 delivers data to the slower
side, the overflow control mechanism in the appliance 200 can
require that a minimum amount of space be available before sending
a nonzero window advertisement to the sender. In one embodiment,
the appliance 200 waits until there is a minimum of a predetermined
number of packets, such as four packets, of space available before
sending a nonzero window packet, such as a window size of four
packet). This reduces the overhead by approximately a factor four,
since only two ACK packets are sent for each group of four data
packets, instead of eight ACK packets for four data packets.
Another technique the appliance 200 or flow controller 220 may use
for overflow control is the TCP delayed ACK mechanism, which skips
ACKs to reduce network traffic. The TCP delayed ACKs automatically
delay the sending of an ACK, either until two packets are received
or until a fixed timeout has occurred. This mechanism alone can
result in cutting the overhead in half; moreover, by increasing the
numbers of packets above two, additional overhead reduction is
realized. But merely delaying the ACK itself may be insufficient to
control overflow, and the appliance 200 may also use the advertised
window mechanism on the ACKs to control the sender. When doing
this, the appliance 200 in one embodiment avoids triggering the
timeout mechanism of the sender by delaying the ACK too long.
In one embodiment, the flow controller 220 does not preack the last
packet of a group of packets. By not preacking the last packet, or
at least one of the packets in the group, the appliance avoids a
false acknowledgement for a group of packets. For example, if the
appliance were to send a preack for a last packet and the packet
were subsequently lost, the sender would have been tricked into
thinking that the packet is delivered when it was not. Thinking
that the packet had been delivered, the sender could discard that
data. If the appliance also lost the packet, there would be no way
to retransmit the packet to the recipient. By not preacking the
last packet of a group of packets, the sender will not discard the
packet until it has been delivered.
In another embodiment, the flow controller 220 may use a window
virtualization technique to control the rate of flow or bandwidth
utilization of a network connection. Though it may not immediately
be apparent from examining conventional literature such as RFC
1323, there is effectively a send window for transport layer
protocols such as TCP. The send window is similar to the receive
window, in that it consumes buffer space (though on the sender).
The sender's send window consists of all data sent by the
application that has not been acknowledged by the receiver. This
data must be retained in memory in case retransmission is required.
Since memory is a shared resource, some TCP stack implementations
limit the size of this data. When the send window is full, an
attempt by an application program to send more data results in
blocking the application program until space is available.
Subsequent reception of acknowledgements will free send-window
memory and unblock the application program. In some embodiments,
this window size is known as the socket buffer size in some TCP
implementations.
In one embodiment, the flow control module 220 is configured to
provide access to increased window (or buffer) sizes. This
configuration may also be referenced to as window virtualization.
In the embodiment of TCP as the transport layer protocol, the TCP
header includes a bit string corresponding to a window scale. In
one embodiment, "window" may be referenced in a context of send,
receive, or both.
One embodiment of window virtualization is to insert a preacking
appliance 200 into a TCP session. In reference to any of the
environments of FIG. 1A or 1B, initiation of a data communication
session between a source node, e.g., client 102 (for ease of
discussion, now referenced as source node 102), and a destination
node, e.g., server 106 (for ease of discussion, now referenced as
destination node 106) is established. For TCP communications, the
source node 102 initially transmits a synchronization signal
("SYN") through its local area network 104 to first flow control
module 220. The first flow control module 220 inserts a
configuration identifier into the TCP header options area. The
configuration identifier identifies this point in the data path as
a flow control module.
The appliances 200 via a flow control module 220 provide window (or
buffer) to allow increasing data buffering capabilities within a
session despite having end nodes with small buffer sizes, e.g.,
typically 16 k bytes. However, RFC 1323 requires window scaling for
any buffer sizes greater than 64 k bytes, which must be set at the
time of session initialization (SYN, SYN-ACK signals). Moreover,
the window scaling corresponds to the lowest common denominator in
the data path, often an end node with small buffer size. This
window scale often is a scale of 0 or 1, which corresponds to a
buffer size of up to 64 k or 128 k bytes. Note that because the
window size is defined as the window field in each packet shifted
over by the window scale, the window scale establishes an upper
limit for the buffer, but does not guarantee the buffer is actually
that large. Each packet indicates the current available buffer
space at the receiver in the window field.
In one embodiment of scaling using the window virtualization
technique, during connection establishment (i.e., initialization of
a session) when the first flow control module 220 receives from the
source node 102 the SYN signal (or packet), the flow control module
220 stores the windows scale of the source node 102 (which is the
previous node) or stores a 0 for window scale if the scale of the
previous node is missing. The first flow control module 220 also
modifies the scale, e.g., increases the scale to 4 from 0 or 1, in
the SYN-FCM signal. When the second flow control module 220
receives the SYN signal, it stores the increased scale from the
first flow control signal and resets the scale in the SYN signal
back to the source node 103 scale value for transmission to the
destination node 106. When the second flow controller 220 receives
the SYN-ACK signal from the destination node 106, it stores the
scale from the destination node 106 scale, e.g., 0 or 1, and
modifies it to an increased scale that is sent with the SYN-ACK-FCM
signal. The first flow control node 220 receives and notes the
received window scale and revises the windows scale sent back to
the source node 102 back down to the original scale, e.g., 0 or 1.
Based on the above window shift conversation during connection
establishment, the window field in every subsequent packet, e.g.,
TCP packet, of the session must be shifted according to the window
shift conversion.
The window scale, as described above, expresses buffer sizes of
over 64 k and may not be required for window virtualization. Thus,
shifts for window scale may be used to express increased buffer
capacity in each flow control module 220. This increase in buffer
capacity in may be referenced as window (or buffer) virtualization.
The increase in buffer size allows greater packet through put from
and to the respective end nodes 102 and 106. Note that buffer sizes
in TCP are typically expressed in terms of bytes, but for ease of
discussion "packets" may be used in the description herein as it
relates to virtualization.
By way of example, a window (or buffer) virtualization performed by
the flow controller 220 is described. In this example, the source
node 102 and the destination node 106 are configured similar to
conventional end nodes having a limited buffer capacity of 16 k
bytes, which equals approximately 10 packets of data. Typically, an
end node 102, 106 must wait until the packet is transmitted and
confirmation is received before a next group of packets can be
transmitted. In one embodiment, using increased buffer capacity in
the flow control modules 220, when the source node 103 transmits
its data packets, the first flow control module 220 receives the
packets, stores it in its larger capacity buffer, e.g., 512 packet
capacity, and immediately sends back an acknowledgement signal
indicating receipt of the packets ("REC-ACK") back to the source
node 102. The source node 102 can then "flush" its current buffer,
load it with 10 new data packets, and transmit those onto the first
flow control module 220. Again, the first flow control module 220
transmits a REC-ACK signal back to the source node 102 and the
source node 102 flushes its buffer and loads it with 10 more new
packets for transmission.
As the first flow control module 220 receives the data packets from
the source nodes, it loads up its buffer accordingly. When it is
ready the first flow control module 220 can begin transmitting the
data packets to the second flow control module 230, which also has
an increased buffer size, for example, to receive 512 packets. The
second flow control module 220' receives the data packets and
begins to transmit 10 packets at a time to the destination node
106. Each REC-ACK received at the second flow control node 220 from
the destination node 106 results in 10 more packets being
transmitted to the destination node 106 until all the data packets
are transferred. Hence, the present disclosure is able to increase
data transmission throughput between the source node (sender) 102
and the destination node (receiver) 106 by taking advantage of the
larger buffer in the flow control modules 220, 220' between the
devices.
It is noted that by "preacking" the transmission of data as
described previously, a sender (or source node 102) is allowed to
transmit more data than is possible without the preacks, thus
affecting a larger window size. For example, in one embodiment this
technique is effective when the flow control module 220, 220' is
located "near" a node (e.g., source node 102 or destination node
106) that lacks large windows.
Recongestion
Another technique or algorithm of the flow controller 220 is
referred to as recongestion. The standard TCP congestion avoidance
algorithms are known to perform poorly in the face of certain
network conditions, including: large RTTs (round trip times), high
packet loss rates, and others. When the appliance 200 detects a
congestion condition such as long round trip times or high packet
loss, the appliance 200 intervenes, substituting an alternate
congestion avoidance algorithm that better suits the particular
network condition. In one embodiment, the recongestion algorithm
uses preacks to effectively terminate the connection between the
sender and the receiver. The appliance 200 then resends the packets
from itself to the receiver, using a different congestion avoidance
algorithm. Recongestion algorithms may be dependent on the
characteristics of the TCP connection. The appliance 200 monitors
each TCP connection, characterizing it with respect to the
different dimensions, selecting a recongestion algorithm that is
appropriate for the current characterization.
In one embodiment, upon detecting a TCP connection that is limited
by round trip times (RTT), a recongestion algorithm is applied
which behaves as multiple TCP connections. Each TCP connection
operates within its own performance limit but the aggregate
bandwidth achieves a higher performance level. One parameter in
this mechanism is the number of parallel connections that are
applied (N). Too large a value of N and the connection bundle
achieves more than its fair share of bandwidth. Too small a value
of N and the connection bundle achieves less than its fair share of
bandwidth. One method of establishing "N" relies on the appliance
200 monitoring the packet loss rate, RTT, and packet size of the
actual connection. These numbers are plugged into a TCP response
curve formula to provide an upper limit on the performance of a
single TCP connection in the present configuration. If each
connection within the connection bundle is achieving substantially
the same performance as that computed to be the upper limit, then
additional parallel connections are applied. If the current bundle
is achieving less performance than the upper limit, the number of
parallel connections is reduced. In this manner, the overall
fairness of the system is maintained since individual connection
bundles contain no more parallelism than is required to eliminate
the restrictions imposed by the protocol itself. Furthermore, each
individual connection retains TCP compliance.
Another method of establishing "N" is to utilize a parallel flow
control algorithm such as the TCP "Vegas" algorithm or its improved
version "Stabilized Vegas." In this method, the network information
associated with the connections in the connection bundle (e.g.,
RTT, loss rate, average packet size, etc.) is aggregated and
applied to the alternate flow control algorithm. The results of
this algorithm are in turn distributed among the connections of the
bundle controlling their number (i.e., N). Optionally, each
connection within the bundle continues using the standard TCP
congestion avoidance algorithm.
In another embodiment, the individual connections within a parallel
bundle are virtualized, i.e., actual individual TCP connections are
not established. Instead the congestion avoidance algorithm is
modified to behave as though there were N parallel connections.
This method has the advantage of appearing to transiting network
nodes as a single connection. Thus the QOS, security and other
monitoring methods of these nodes are unaffected by the
recongestion algorithm. In yet another embodiment, the individual
connections within a parallel bundle are real, i.e., a separate.
TCP connection is established for each of the parallel connections
within a bundle. The congestion avoidance algorithm for each TCP
connection need not be modified.
Retransmission
In some embodiments, the flow controller 220 may apply a local
retransmission technique. One reason for implementing preacks is to
prepare to transit a high-loss link (e.g., wireless). In these
embodiments, the preacking appliance 200 or flow control module 220
is located most beneficially "before" the wireless link. This
allows retransmissions to be performed closer to the high loss
link, removing the retransmission burden from the remainder of the
network. The appliance 200 may provide local retransmission, in
which case, packets dropped due to failures of the link are
retransmitted directly by the appliance 200. This is advantageous
because it eliminates the retransmission burden upon an end node,
such as server 106, and infrastructure of any of the networks 104.
With appliance 200 providing local retransmissions, the dropped
packet can be retransmitted across the high loss link without
necessitating a retransmit by an end node and a corresponding
decrease in the rate of data transmission from the end node.
Another reason for implementing preacks is to avoid a receive time
out (RTO) penalty. In standard TCP there are many situations that
result in an RTO, even though a large percentage of the packets in
flight were successfully received. With standard TCP algorithms,
dropping more than one packet within an RTT window would likely
result in a timeout. Additionally, most TCP connections experience
a timeout if a retransmitted packet is dropped. In a network with a
high bandwidth delay product, even a relatively small packet loss
rate will cause frequent Retransmission timeouts (RTOs). In one
embodiment, the appliance 200 uses a retransmit and timeout
algorithm is avoid premature RTOs. The appliance 200 or flow
controller 220 maintains a count of retransmissions is maintained
on a per-packet basis. Each time that a packet is retransmitted,
the count is incremented by one and the appliance 200 continues to
transmit packets. In some embodiments, only if a packet has been
retransmitted a predetermined number of times is an RTO
declared.
Wavefront Detection and Disambiguation
In some embodiments, the appliance 200 or flow controller 220 uses
wavefront detection and disambiguation techniques in managing and
controlling flow of network traffic. In this technique, the flow
controller 220 uses transmit identifiers or numbers to determine
whether particular data packets need to be retransmitted. By way of
example, a sender transmits data packets over a network, where each
instance of a transmitted data packet is associated with a transmit
number. It can be appreciated that the transmit number for a packet
is not the same as the packet's sequence number, since a sequence
number references the data in the packet while the transmit number
references an instance of a transmission of that data. The transmit
number can be any information usable for this purpose, including a
timestamp associated with a packet or simply an increasing number
(similar to a sequence number or a packet number). Because a data
segment may be retransmitted, different transmit numbers may be
associated with a particular sequence number.
As the sender transmits data packets, the sender maintains a data
structure of acknowledged instances of data packet transmissions.
Each instance of a data packet transmission is referenced by its
sequence number and transmit number. By maintaining a transmit
number for each packet, the sender retains the ordering of the
transmission of data packets. When the sender receives an ACK or a
SACK, the sender determines the highest transmit number associated
with packets that the receiver indicated has arrived (in the
received acknowledgement). Any outstanding unacknowledged packets
with lower transmit numbers are presumed lost.
In some embodiments, the sender is presented with an ambiguous
situation when the arriving packet has been retransmitted: a
standard ACK/SACK does not contain enough information to allow the
sender to determine which transmission of the arriving packet has
triggered the acknowledgement. After receiving an ambiguous
acknowledgement, therefore, the sender disambiguates the
acknowledgement to associate it with a transmit number. In various
embodiments, one or a combination of several techniques may be used
to resolve this ambiguity.
In one embodiment, the sender includes an identifier with a
transmitted data packet, and the receiver returns that identifier
or a function thereof with the acknowledgement. The identifier may
be a timestamp (e.g., a TCP timestamp as described in RFC 1323), a
sequential number, or any other information that can be used to
resolve between two or more instances of a packet's transmission.
In an embodiment in which the TCP timestamp option is used to
disambiguate the acknowledgement, each packet is tagged with up to
32-bits of unique information. Upon receipt of the data packet, the
receiver echoes this unique information back to the sender with the
acknowledgement. The sender ensures that the originally sent packet
and its retransmitted version or versions contain different values
for the timestamp option, allowing it to unambiguously eliminate
the ACK ambiguity. The sender may maintain this unique information,
for example, in the data structure in which it stores the status of
sent data packets. This technique is advantageous because it
complies with industry standards and is thus likely to encounter
little or no interoperability issues. However, this technique may
require ten bytes of TCP header space in some implementations,
reducing the effective throughput rate on the network and reducing
space available for other TCP options.
In another embodiment, another field in the packet, such as the IP
ID field, is used to disambiguate in a way similar to the TCP
timestamp option described above. The sender arranges for the ID
field values of the original and the retransmitted version or
versions of the packet to have different ID fields in the IP
header. Upon reception of the data packet at the receiver, or a
proxy device thereof, the receiver sets the ID field of the ACK
packet to a function of the ID field of the packet that triggers
the ACK. This method is advantageous, as it requires no additional
data to be sent, preserving the efficiency of the network and TCP
header space. The function chosen should provide a high degree of
likelihood of providing disambiguation. In a preferred embodiment,
the sender selects IP ID values with the most significant bit set
to 0. When the receiver responds, the IP ID value is set to the
same IP ID value with the most significant bit set to a one.
In another embodiment, the transmit numbers associated with
non-ambiguous acknowledgements are used to disambiguate an
ambiguous acknowledgement. This technique is based on the principle
that acknowledgements for two packets will tend to be received
closer in time as the packets are transmitted closer in time.
Packets that are not retransmitted will not result in ambiguity, as
the acknowledgements received for such packets can be readily
associated with a transmit number. Therefore, these known transmit
numbers are compared to the possible transmit numbers for an
ambiguous acknowledgement received near in time to the known
acknowledgement. The sender compares the transmit numbers of the
ambiguous acknowledgement against the last known received transmit
number, selecting the one closest to the known received transmit
number. For example, if an acknowledgement for data packet 1 is
received and the last received acknowledgement was for data packet
5, the sender resolves the ambiguity by assuming that the third
instance of data packet 1 caused the acknowledgement.
Selective Acknowledgements
Another technique of the appliance 200 or flow controller 220 is to
implement an embodiment of transport control protocol selective
acknowledgements, or TCP SACK, to determine what packets have or
have not been received. This technique allows the sender to
determine unambiguously a list of packets that have been received
by the receiver as well as an accurate list of packets not
received. This functionality may be implemented by modifying the
sender and/or receiver, or by inserting sender- and receiver-side
flow control modules 220 in the network path between the sender and
receiver. In reference to FIG. 1A or FIG. 1B, a sender, e.g.,
client 102, is configured to transmit data packets to the receiver,
e.g., server 106, over the network 104. In response, the receiver
returns a TCP Selective Acknowledgment option, referred to as SACK
packet to the sender. In one embodiment, the communication is
bi-directional, although only one direction of communication is
discussed here for simplicity. The receiver maintains a list, or
other suitable data structure, that contains a group of ranges of
sequence numbers for data packets that the receiver has actually
received. In some embodiments, the list is sorted by sequence
number in an ascending or descending order. The receiver also
maintains a left-off pointer, which comprises a reference into the
list and indicates the left-off point from the previously generated
SACK packet.
Upon reception of a data packet, the receiver generates and
transmits a SACK packet back to the sender. In some embodiments,
the SACK packet includes a number of fields, each of which can hold
a range of sequence numbers to indicate a set of received data
packets. The receiver fills this first field of the SACK packet
with a range of sequence numbers that includes the landing packet
that triggered the SACK packet. The remaining available SACK fields
are filled with ranges of sequence numbers from the list of
received packets. As there are more ranges in the list than can be
loaded into the SACK packet, the receiver uses the left-off pointer
to determine which ranges are loaded into the SACK packet. The
receiver inserts the SACK ranges consecutively from the sorted
list, starting from the range referenced by the pointer and
continuing down the list until the available SACK range space in
the TCP header of the SACK packet is consumed. The receiver wraps
around to the start of the list if it reaches the end. In some
embodiments, two or three additional SACK ranges can be added to
the SACK range information.
Once the receiver generates the SACK packet, the receiver sends the
acknowledgement back to the sender. The receiver then advances the
left-off pointer by one or more SACK range entries in the list. If
the receiver inserts four SACK ranges, for example, the left-off
pointer may be advanced two SACK ranges in the list. When the
advanced left-off pointer reaches at the end of the list, the
pointer is reset to the start of the list, effectively wrapping
around the list of known received ranges. Wrapping around the list
enables the system to perform well, even in the presence of large
losses of SACK packets, since the SACK information that is not
communicated due to a lost SACK packet will eventually be
communicated once the list is wrapped around.
It can be appreciated, therefore, that a SACK packet may
communicate several details about the condition of the receiver.
First, the SACK packet indicates that, upon generation of the SACK
packet, the receiver had just received a data packet that is within
the first field of the SACK information. Secondly, the second and
subsequent fields of the SACK information indicate that the
receiver has received the data packets within those ranges. The
SACK information also implies that the receiver had not, at the
time of the SACK packet's generation, received any of the data
packets that fall between the second and subsequent fields of the
SACK information. In essence, the ranges between the second and
subsequent ranges in the SACK information are "holes" in the
received data, the data therein known not to have been delivered.
Using this method, therefore, when a SACK packet has sufficient
space to include more than two SACK ranges, the receiver may
indicate to the sender a range of data packets that have not yet
been received by the receiver.
In another embodiment, the sender uses the SACK packet described
above in combination with the retransmit technique described above
to make assumptions about which data packets have been delivered to
the receiver. For example, when the retransmit algorithm (using the
transmit numbers) declares a packet lost, the sender considers the
packet to be only conditionally lost, as it is possible that the
SACK packet identifying the reception of this packet was lost
rather than the data packet itself. The sender thus adds this
packet to a list of potentially lost packets, called the presumed
lost list. Each time a SACK packet arrives, the known missing
ranges of data from the SACK packet are compared to the packets in
the presumed lost list. Packets that contain data known to be
missing are declared actually lost and are subsequently
retransmitted. In this way, the two schemes are combined to give
the sender better information about which packets have been lost
and need to be retransmitted.
Transaction Boundary Detection
In some embodiments, the appliance 200 or flow controller 220
applies a technique referred to as transaction boundary detection.
In one embodiment, the technique pertains to ping-pong behaved
connections. At the TCP layer, ping-pong behavior is when one
communicant--a sender--sends data and then waits for a response
from the other communicant--the receiver. Examples of ping-pong
behavior include remote procedure call, HTTP and others. The
algorithms described above use retransmission timeout (RTO) to
recover from the dropping of the last packet or packets associated
with the transaction. Since the TCP RTO mechanism is extremely
coarse in some embodiments, for example requiring a minimum one
second value in all cases, poor application behavior may be seen in
these situations.
In one embodiment, the sender of data or a flow control module 220
coupled to the sender detects a transaction boundary in the data
being sent. Upon detecting a transaction boundary, the sender or a
flow control module 220 sends additional packets, whose reception
generates additional ACK or SACK responses from the receiver.
Insertion of the additional packets is preferably limited to
balance between improved application response time and network
capacity utilization. The number of additional packets that is
inserted may be selected according to the current loss rate
associated with that connection, with more packets selected for
connections having a higher loss rate.
One method of detecting a transaction boundary is time based. If
the sender has been sending data and ceases, then after a period of
time the sender or flow control module 200 declares a transaction
boundary. This may be combined with other techniques. For example,
the setting of the PSH (TCP Push) bit by the sender in the TCP
header may indicate a transaction boundary. Accordingly, combining
the time-based approach with these additional heuristics can
provide for more accurate detection of a transaction boundary. In
another technique, if the sender or flow control module 220
understands the application protocol, it can parse the protocol
data stream and directly determine transaction boundaries. In some
embodiment, this last behavior can be used independent of any
time-based mechanism.
Responsive to detecting a transaction boundary, the sender or flow
control module 220 transmits additional data packets to the
receiver to cause acknowledgements therefrom. The additional data
packets should therefore be such that the receiver will at least
generate an ACK or SACK in response to receiving the data packet.
In one embodiment, the last packet or packets of the transaction
are simply retransmitted. This has the added benefit of
retransmitting needed data if the last packet or packets had been
dropped, as compared to merely sending dummy data packets. In
another embodiment, fractions of the last packet or packets are
sent, allowing the sender to disambiguate the arrival of these
packets from their original packets. This allows the receiver to
avoid falsely confusing any reordering adaptation algorithms. In
another embodiment, any of a number of well-known forward error
correction techniques can be used to generate additional data for
the inserted packets, allowing for the reconstruction of dropped or
otherwise missing data at the receiver.
In some embodiments, the boundary detection technique described
herein helps to avoid a timeout when the acknowledgements for the
last data packets in a transaction are dropped. When the sender or
flow control module 220 receives the acknowledgements for these
additional data packets, the sender can determine from these
additional acknowledgements whether the last data packets have been
received or need to be retransmitted, thus avoiding a timeout. In
one embodiment, if the last packets have been received but their
acknowledgements were dropped, a flow control module 220 generates
an acknowledgement for the data packets and sends the
acknowledgement to the sender, thus communicating to the sender
that the data packets have been delivered. In another embodiment,
if the last packets have not been received, a flow control module
200 sends a packet to the sender to cause the sender to retransmit
the dropped data packets.
Repacketization
In yet another embodiment, the appliance 200 or flow controller 220
applies a repacketization technique for improving the flow of
transport layer network traffic. In some embodiments, performance
of TCP is proportional to packet size. Thus increasing packet sizes
improves performance unless it causes substantially increased
packet loss rates or other nonlinear effects, like IP
fragmentation. In general, wired media (such as copper or fibre
optics) have extremely low bit-error rates, low enough that these
can be ignored. For these media, it is advantageous for the packet
size to be the maximum possible before fragmentation occurs (the
maximum packet size is limited by the protocols of the underlying
transmission media). Whereas for transmission media with higher
loss rates (e.g., wireless technologies such as WiFi, etc., or
high-loss environments such as power-line networking, etc.),
increasing the packet size may lead to lower transmission rates, as
media-induced errors cause an entire packet to be dropped (i.e.,
media-induced errors beyond the capability of the standard error
correcting code for that media), increasing the packet loss rate. A
sufficiently large increase in the packet loss rate will actually
negate any performance benefit of increasing packet size. In some
cases, it may be difficult for a TCP endpoint to choose an optimal
packet size. For example, the optimal packet size may vary across
the transmission path, depending on the nature of each link.
By inserting an appliance 200 or flow control module 220 into the
transmission path, the flow controller 220 monitors characteristics
of the link and repacketizes according to determined link
characteristics. In one embodiment, an appliance 200 or flow
controller 220 repacketizes packets with sequential data into a
smaller number of larger packets. In another embodiment, an
appliance 200 or flow controller 220 repacketizes packets by
breaking part a sequence of large packets into a larger number of
smaller packets. In other embodiments, an appliance 200 or flow
controller 220 monitors the link characteristics and adjusts the
packet sizes through recombination to improve throughput.
QoS
Still referring to FIG. 2A, the flow controller 220, in some
embodiments, may include a QoS Engine 236, also referred to as a
QoS controller. In another embodiment, the appliance 200 and/or
network optimization engine 250 includes the QoS engine 236, for
example, separately but in communication with the flow controller
220. The QoS Engine 236 includes any logic, business rules,
function or operations for performing one or more Quality of
Service (QoS) techniques improving the performance, operation or
quality of service of any of the network connections. In some
embodiments, the QoS engine 236 includes network traffic control
and management mechanisms that provide different priorities to
different users, applications, data flows or connections. In other
embodiments, the QoS engine 236 controls, maintains, or assures a
certain level of performance to a user, application, data flow or
connection. In one embodiment, the QoS engine 236 controls,
maintains or assures a certain portion of bandwidth or network
capacity for a user, application, data flow or connection. In some
embodiments, the QoS engine 236 monitors the achieved level of
performance or the quality of service corresponding to a user,
application, data flow or connection, for example, the data rate
and delay. In response to monitoring, the QoS engine 236
dynamically controls or adjusts scheduling priorities of network
packets to achieve the desired level of performance or quality of
service.
In some embodiments, the QoS engine 236 prioritizes, schedules and
transmits network packets according to one or more classes or
levels of services. In some embodiments, the class or level service
may include: 1) best efforts, 2) controlled load, 3) guaranteed or
4) qualitative. For a best efforts class of service, the appliance
200 makes reasonable effort to deliver packets (a standard service
level). For a controlled load class of service, the appliance 200
or QoS engine 236 approximates the standard packet error loss of
the transmission medium or approximates the behavior of best-effort
service in lightly loaded network conditions. For a guaranteed
class of service, the appliance 200 or QoS engine 236 guarantees
the ability to transmit data at a determined rate for the duration
of the connection. For a qualitative class of service, the
appliance 200 or QoS engine 236 the qualitative service class is
used for applications, users, data flows or connection that require
or desire prioritized traffic but cannot quantify resource needs or
level of service. In these cases, the appliance 200 or QoS engine
236 determines the class of service or prioritization based on any
logic or configuration of the QoS engine 236 or based on business
rules or policies. For example, in one embodiment, the QoS engine
236 prioritizes, schedules and transmits network packets according
to one or more policies as specified by the policy engine 295,
295'.
Protocol Acceleration
The protocol accelerator 234 includes any logic, business rules,
function or operations for optimizing, accelerating, or otherwise
improving the performance, operation or quality of service of one
or more protocols. In one embodiment, the protocol accelerator 234
accelerates any application layer protocol or protocols at layers
5-7 of the network stack. In other embodiments, the protocol
accelerator 234 accelerates a transport layer or a layer 4
protocol. In one embodiment, the protocol accelerator 234
accelerates layer 2 or layer 3 protocols. In some embodiments, the
protocol accelerator 234 is configured, constructed or designed to
optimize or accelerate each of one or more protocols according to
the type of data, characteristics and/or behavior of the protocol.
In another embodiment, the protocol accelerator 234 is configured,
constructed or designed to improve a user experience, response
times, network or computer load, and/or network or bandwidth
utilization with respect to a protocol.
In one embodiment, the protocol accelerator 234 is configured,
constructed or designed to minimize the effect of WAN latency on
file system access. In some embodiments, the protocol accelerator
234 optimizes or accelerates the use of the CIFS (Common Internet
File System) protocol to improve file system access times or access
times to data and files. In some embodiments, the protocol
accelerator 234 optimizes or accelerates the use of the NFS
(Network File System) protocol. In another embodiment, the protocol
accelerator 234 optimizes or accelerates the use of the File
Transfer protocol (FTP).
In one embodiment, the protocol accelerator 234 is configured,
constructed or designed to optimize or accelerate a protocol
carrying as a payload or using any type and form of markup
language. In other embodiments, the protocol accelerator 234 is
configured, constructed or designed to optimize or accelerate a
HyperText Transfer Protocol (HTTP). In another embodiment, the
protocol accelerator 234 is configured, constructed or designed to
optimize or accelerate a protocol carrying as a payload or
otherwise using XML (eXtensible Markup Language).
Transparency and Multiple Deployment Configuration
In some embodiments, the appliance 200 and/or network optimization
engine 250 is transparent to any data flowing across a network
connection or link, such as a WAN link. In one embodiment, the
appliance 200 and/or network optimization engine 250 operates in
such a manner that the data flow across the WAN is recognizable by
any network monitoring, QOS management or network analysis tools.
In some embodiments, the appliance 200 and/or network optimization
engine 250 does not create any tunnels or streams for transmitting
data that may hide, obscure or otherwise make the network traffic
not transparent. In other embodiments, the appliance 200 operates
transparently in that the appliance does not change any of the
source and/or destination address information or port information
of a network packet, such as internet protocol addresses or port
numbers. In other embodiments, the appliance 200 and/or network
optimization engine 250 is considered to operate or behave
transparently to the network, an application, client, server or
other appliances or computing device in the network infrastructure.
That is, in some embodiments, the appliance is transparent in that
network related configuration of any device or appliance on the
network does not need to be modified to support the appliance
200.
The appliance 200 may be deployed in any of the following
deployment configurations: 1) in-line of traffic, 2) in proxy mode,
or 3) in a virtual in-line mode. In some embodiments, the appliance
200 may be deployed inline to one or more of the following: a
router, a client, a server or another network device or appliance.
In other embodiments, the appliance 200 may be deployed in parallel
to one or more of the following: a router, a client, a server or
another network device or appliance. In parallel deployments, a
client, server, router or other network appliance may be configured
to forward, transfer or transit networks to or via the appliance
200.
In the embodiment of in-line, the appliance 200 is deployed inline
with a WAN link of a router. In this way, all traffic from the WAN
passes through the appliance before arriving at a destination of a
LAN.
In the embodiment of a proxy mode, the appliance 200 is deployed as
a proxy device between a client and a server. In some embodiments,
the appliance 200 allows clients to make indirect connections to a
resource on a network. For example, a client connects to a resource
via the appliance 200, and the appliance provides the resource
either by connecting to the resource, a different resource, or by
serving the resource from a cache. In some cases, the appliance may
alter the client's request or the server's response for various
purposes, such as for any of the optimization techniques discussed
herein. In other embodiments, the appliance 200 behaves as a
transparent proxy, by intercepting and forwarding requests and
responses transparently to a client and/or server. Without
client-side configuration, the appliance 200 may redirect client
requests to different servers or networks. In some embodiments, the
appliance 200 may perform any type and form of network address
translation, referred to as NAT, on any network traffic traversing
the appliance.
In some embodiments, the appliance 200 is deployed in a virtual
in-line mode configuration. In this embodiment, a router or a
network device with routing or switching functionality is
configured to forward, reroute or otherwise provide network packets
destined to a network to the appliance 200. The appliance 200 then
performs any desired processing on the network packets, such as any
of the WAN optimization techniques discussed herein. Upon
completion of processing, the appliance 200 forwards the processed
network packet to the router to transmit to the destination on the
network. In this way, the appliance 200 can be coupled to the
router in parallel but still operate as it if the appliance 200
were inline. This deployment mode also provides transparency in
that the source and destination addresses and port information are
preserved as the packet is processed and transmitted via the
appliance through the network.
End Node Deployment
Although the network optimization engine 250 is generally described
above in conjunction with an appliance 200, the network
optimization engine 250, or any portion thereof, may be deployed,
distributed or otherwise operated on any end node, such as a client
102 and/or server 106. As such, a client or server may provide any
of the systems and methods of the network optimization engine 250
described herein in conjunction with one or more appliances 200 or
without an appliance 200.
Referring now to FIG. 2B, an example embodiment of the network
optimization engine 250 deployed on one or more end nodes is
depicted. In brief overview, the client 102 may include a first
network optimization engine 250' and the server 106 may include a
second network optimization engine 250''. The client 102 and server
106 may establish a transport layer connection and exchange
communications with or without traversing an appliance 200.
In one embodiment, the network optimization engine 250' of the
client 102 performs the techniques described herein to optimize,
accelerate or otherwise improve the performance, operation or
quality of service of network traffic communicated with the server
106. In another embodiment, the network optimization engine 250''
of the server 106 performs the techniques described herein to
optimize, accelerate or otherwise improve the performance,
operation or quality of service of network traffic communicated
with the client 102. In some embodiments, the network optimization
engine 250' of the client 102 and the network optimization engine
250'' of the server 106 perform the techniques described herein to
optimize, accelerate or otherwise improve the performance,
operation or quality of service of network traffic communicated
between the client 102 and the server 106. In yet another
embodiment, the network optimization engine 250' of the client 102
performs the techniques described herein in conjunction with an
appliance 200 to optimize, accelerate or otherwise improve the
performance, operation or quality of service of network traffic
communicated with the client 102. In still another embodiment, the
network optimization engine 250'' of the server 106 performs the
techniques described herein in conjunction with an appliance 200 to
optimize, accelerate or otherwise improve the performance,
operation or quality of service of network traffic communicated
with the server 106.
C. Client Agent
Referring now to FIG. 3, an embodiment of a client agent 120 is
depicted. The client 102 has a client agent 120 for establishing,
exchanging, managing or controlling communications with the
appliance 200, appliance 205 and/or server 106 via a network 104.
In some embodiments, the client agent 120, which may also be
referred to as a WAN client, accelerates WAN network communications
and/or is used to communicate via appliance 200 on a network. In
brief overview, the client 102 operates on computing device 100
having an operating system with a kernel mode 302 and a user mode
303, and a network stack 267 with one or more layers 310a-310b. The
client 102 may have installed and/or execute one or more
applications. In some embodiments, one or more applications may
communicate via the network stack 267 to a network 104. One of the
applications, such as a web browser, may also include a first
program 322. For example, the first program 322 may be used in some
embodiments to install and/or execute the client agent 120, or any
portion thereof. The client agent 120 includes an interception
mechanism, or interceptor 350, for intercepting network
communications from the network stack 267 from the one or more
applications.
As with the appliance 200, the client has a network stack 267
including any type and form of software, hardware, or any
combinations thereof, for providing connectivity to and
communications with a network 104. The network stack 267 of the
client 102 includes any of the network stack embodiments described
above in conjunction with the appliance 200. In some embodiments,
the client agent 120, or any portion thereof, is designed and
constructed to operate with or work in conjunction with the network
stack 267 installed or otherwise provided by the operating system
of the client 102.
In further details, the network stack 267 of the client 102 or
appliance 200 (or 205) may include any type and form of interfaces
for receiving, obtaining, providing or otherwise accessing any
information and data related to network communications of the
client 102. In one embodiment, an interface to the network stack
267 includes an application programming interface (API). The
interface may also have any function call, hooking or filtering
mechanism, event or call back mechanism, or any type of interfacing
technique. The network stack 267 via the interface may receive or
provide any type and form of data structure, such as an object,
related to functionality or operation of the network stack 267. For
example, the data structure may include information and data
related to a network packet or one or more network packets. In some
embodiments, the data structure includes, references or identifies
a portion of the network packet processed at a protocol layer of
the network stack 267, such as a network packet of the transport
layer. In some embodiments, the data structure 325 is a
kernel-level data structure, while in other embodiments, the data
structure 325 is a user-mode data structure. A kernel-level data
structure may have a data structure obtained or related to a
portion of the network stack 267 operating in kernel-mode 302, or a
network driver or other software running in kernel-mode 302, or any
data structure obtained or received by a service, process, task,
thread or other executable instructions running or operating in
kernel-mode of the operating system.
Additionally, some portions of the network stack 267 may execute or
operate in kernel-mode 302, for example, the data link or network
layer, while other portions execute or operate in user-mode 303,
such as an application layer of the network stack 267. For example,
a first portion 310a of the network stack may provide user-mode
access to the network stack 267 to an application while a second
portion 310a of the network stack 267 provides access to a network.
In some embodiments, a first portion 310a of the network stack has
one or more upper layers of the network stack 267, such as any of
layers 5-7. In other embodiments, a second portion 310b of the
network stack 267 includes one or more lower layers, such as any of
layers 1-4. Each of the first portion 310a and second portion 310b
of the network stack 267 may include any portion of the network
stack 267, at any one or more network layers, in user-mode 303,
kernel-mode, 302, or combinations thereof, or at any portion of a
network layer or interface point to a network layer or any portion
of or interface point to the user-mode 302 and kernel-mode 203.
The interceptor 350 may include software, hardware, or any
combination of software and hardware. In one embodiment, the
interceptor 350 intercepts or otherwise receives a network
communication at any point in the network stack 267, and redirects
or transmits the network communication to a destination desired,
managed or controlled by the interceptor 350 or client agent 120.
For example, the interceptor 350 may intercept a network
communication of a network stack 267 of a first network and
transmit the network communication to the appliance 200 for
transmission on a second network 104. In some embodiments, the
interceptor 350 includes or is a driver, such as a network driver
constructed and designed to interface and work with the network
stack 267. In some embodiments, the client agent 120 and/or
interceptor 350 operates at one or more layers of the network stack
267, such as at the transport layer. In one embodiment, the
interceptor 350 includes a filter driver, hooking mechanism, or any
form and type of suitable network driver interface that interfaces
to the transport layer of the network stack, such as via the
transport driver interface (TDI). In some embodiments, the
interceptor 350 interfaces to a first protocol layer, such as the
transport layer and another protocol layer, such as any layer above
the transport protocol layer, for example, an application protocol
layer. In one embodiment, the interceptor 350 includes a driver
complying with the Network Driver Interface Specification (NDIS),
or a NDIS driver. In another embodiment, the interceptor 350 may be
a min-filter or a mini-port driver. In one embodiment, the
interceptor 350, or portion thereof, operates in kernel-mode 202.
In another embodiment, the interceptor 350, or portion thereof,
operates in user-mode 203. In some embodiments, a portion of the
interceptor 350 operates in kernel-mode 202 while another portion
of the interceptor 350 operates in user-mode 203. In other
embodiments, the client agent 120 operates in user-mode 203 but
interfaces via the interceptor 350 to a kernel-mode driver,
process, service, task or portion of the operating system, such as
to obtain a kernel-level data structure 225. In further
embodiments, the interceptor 350 is a user-mode application or
program, such as application.
In one embodiment, the interceptor 350 intercepts or receives any
transport layer connection requests. In these embodiments, the
interceptor 350 executes transport layer application programming
interface (API) calls to set the destination information, such as
destination IP address and/or port to a desired location for the
location. In this manner, the interceptor 350 intercepts and
redirects the transport layer connection to an IP address and port
controlled or managed by the interceptor 350 or client agent 120.
In one embodiment, the interceptor 350 sets the destination
information for the connection to a local IP address and port of
the client 102 on which the client agent 120 is listening. For
example, the client agent 120 may comprise a proxy service
listening on a local IP address and port for redirected transport
layer communications. In some embodiments, the client agent 120
then communicates the redirected transport layer communication to
the appliance 200.
In some embodiments, the interceptor 350 intercepts a Domain Name
Service (DNS) request. In one embodiment, the client agent 120
and/or interceptor 350 resolves the DNS request. In another
embodiment, the interceptor transmits the intercepted DNS request
to the appliance 200 for DNS resolution. In one embodiment, the
appliance 200 resolves the DNS request and communicates the DNS
response to the client agent 120. In some embodiments, the
appliance 200 resolves the DNS request via another appliance 200'
or a DNS server 106.
In yet another embodiment, the client agent 120 may include two
agents 120 and 120'. In one embodiment, a first agent 120 may
include an interceptor 350 operating at the network layer of the
network stack 267. In some embodiments, the first agent 120
intercepts network layer requests such as Internet Control Message
Protocol (ICMP) requests (e.g., ping and traceroute). In other
embodiments, the second agent 120' may operate at the transport
layer and intercept transport layer communications. In some
embodiments, the first agent 120 intercepts communications at one
layer of the network stack 210 and interfaces with or communicates
the intercepted communication to the second agent 120'.
The client agent 120 and/or interceptor 350 may operate at or
interface with a protocol layer in a manner transparent to any
other protocol layer of the network stack 267. For example, in one
embodiment, the interceptor 350 operates or interfaces with the
transport layer of the network stack 267 transparently to any
protocol layer below the transport layer, such as the network
layer, and any protocol layer above the transport layer, such as
the session, presentation or application layer protocols. This
allows the other protocol layers of the network stack 267 to
operate as desired and without modification for using the
interceptor 350. As such, the client agent 120 and/or interceptor
350 can interface with the transport layer to secure, optimize,
accelerate, route or load-balance any communications provided via
any protocol carried by the transport layer, such as any
application layer protocol over TCP/IP.
Furthermore, the client agent 120 and/or interceptor 350 may
operate at or interface with the network stack 267 in a manner
transparent to any application, a user of the client 102, the
client 102 and/or any other computing device 100, such as a server
or appliance 200, 206, in communications with the client 102. The
client agent 120, or any portion thereof, may be installed and/or
executed on the client 102 in a manner without modification of an
application. In one embodiment, the client agent 120, or any
portion thereof, is installed and/or executed in a manner
transparent to any network configuration of the client 102,
appliance 200, 205 or server 106. In some embodiments, the client
agent 120, or any portion thereof, is installed and/or executed
with modification to any network configuration of the client 102,
appliance 200, 205 or server 106. In one embodiment, the user of
the client 102 or a computing device in communications with the
client 102 are not aware of the existence, execution or operation
of the client agent 12, or any portion thereof. As such, in some
embodiments, the client agent 120 and/or interceptor 350 is
installed, executed, and/or operated transparently to an
application, user of the client 102, the client 102, another
computing device, such as a server or appliance 200, 2005, or any
of the protocol layers above and/or below the protocol layer
interfaced to by the interceptor 350.
The client agent 120 includes a streaming client 306, a collection
agent 304, SSL VPN agent 308, a network optimization engine 250,
and/or acceleration program 302. In one embodiment, the client
agent 120 is an Independent Computing Architecture (ICA) client, or
any portion thereof, developed by Citrix Systems, Inc. of Fort
Lauderdale, Fla., and is also referred to as an ICA client. In some
embodiments, the client agent 120 has an application streaming
client 306 for streaming an application from a server 106 to a
client 102. In another embodiment, the client agent 120 includes a
collection agent 304 for performing end-point detection/scanning
and collecting end-point information for the appliance 200 and/or
server 106. In some embodiments, the client agent 120 has one or
more network accelerating or optimizing programs or agents, such as
an network optimization engine 250 and an acceleration program 302.
In one embodiment, the acceleration program 302 accelerates
communications between client 102 and server 106 via appliance
205'. In some embodiments, the network optimization engine 250
provides WAN optimization techniques as discussed herein.
The streaming client 306 is an application, program, process,
service, task or set of executable instructions for receiving and
executing a streamed application from a server 106. A server 106
may stream one or more application data files to the streaming
client 306 for playing, executing or otherwise causing to be
executed the application on the client 102. In some embodiments,
the server 106 transmits a set of compressed or packaged
application data files to the streaming client 306. In some
embodiments, the plurality of application files are compressed and
stored on a file server within an archive file such as a CAB, ZIP,
SIT, TAR, JAR or other archive. In one embodiment, the server 106
decompresses, unpackages or unarchives the application files and
transmits the files to the client 102. In another embodiment, the
client 102 decompresses, unpackages or unarchives the application
files. The streaming client 306 dynamically installs the
application, or portion thereof, and executes the application. In
one embodiment, the streaming client 306 may be an executable
program. In some embodiments, the streaming client 306 may be able
to launch another executable program.
The collection agent 304 is an application, program, process,
service, task or set of executable instructions for identifying,
obtaining and/or collecting information about the client 102. In
some embodiments, the appliance 200 transmits the collection agent
304 to the client 102 or client agent 120. The collection agent 304
may be configured according to one or more policies of the policy
engine 236 of the appliance. In other embodiments, the collection
agent 304 transmits collected information on the client 102 to the
appliance 200. In one embodiment, the policy engine 236 of the
appliance 200 uses the collected information to determine and
provide access, authentication and authorization control of the
client's connection to a network 104.
In one embodiment, the collection agent 304 is an end-point
detection and scanning program, which identifies and determines one
or more attributes or characteristics of the client. For example,
the collection agent 304 may identify and determine any one or more
of the following client-side attributes: 1) the operating system
an/or a version of an operating system, 2) a service pack of the
operating system, 3) a running service, 4) a running process, and
5) a file. The collection agent 304 may also identify and determine
the presence or version of any one or more of the following on the
client: 1) antivirus software, 2) personal firewall software, 3)
anti-spam software, and 4) internet security software. The policy
engine 236 may have one or more policies based on any one or more
of the attributes or characteristics of the client or client-side
attributes.
The SSL VPN agent 308 is an application, program, process, service,
task or set of executable instructions for establishing a Secure
Socket Layer (SSL) virtual private network (VPN) connection from a
first network 104 to a second network 104', 104'', or a SSL VPN
connection from a client 102 to a server 106. In one embodiment,
the SSL VPN agent 308 establishes a SSL VPN connection from a
public network 104 to a private network 104' or 104''. In some
embodiments, the SSL VPN agent 308 works in conjunction with
appliance 205 to provide the SSL VPN connection. In one embodiment,
the SSL VPN agent 308 establishes a first transport layer
connection with appliance 205. In some embodiment, the appliance
205 establishes a second transport layer connection with a server
106. In another embodiment, the SSL VPN agent 308 establishes a
first transport layer connection with an application on the client,
and a second transport layer connection with the appliance 205. In
other embodiments, the SSL VPN agent 308 works in conjunction with
WAN optimization appliance 200 to provide SSL VPN connectivity.
In some embodiments, the acceleration program 302 is a client-side
acceleration program for performing one or more acceleration
techniques to accelerate, enhance or otherwise improve a client's
communications with and/or access to a server 106, such as
accessing an application provided by a server 106. The logic,
functions, and/or operations of the executable instructions of the
acceleration program 302 may perform one or more of the following
acceleration techniques: 1) multi-protocol compression, 2)
transport control protocol pooling, 3) transport control protocol
multiplexing, 4) transport control protocol buffering, and 5)
caching via a cache manager. Additionally, the acceleration program
302 may perform encryption and/or decryption of any communications
received and/or transmitted by the client 102. In some embodiments,
the acceleration program 302 performs one or more of the
acceleration techniques in an integrated manner or fashion.
Additionally, the acceleration program 302 can perform compression
on any of the protocols, or multiple-protocols, carried as a
payload of a network packet of the transport layer protocol.
In one embodiment, the acceleration program 302 is designed,
constructed or configured to work with appliance 205 to provide LAN
side acceleration or to provide acceleration techniques provided
via appliance 205. For example, in one embodiment of a NetScaler
appliance 205 manufactured by Citrix Systems, Inc., the
acceleration program 302 includes a NetScaler client. In some
embodiments, the acceleration program 302 provides NetScaler
acceleration techniques stand-alone in a remote device, such as in
a branch office. In other embodiments, the acceleration program 302
works in conjunction with one or more NetScaler appliances 205. In
one embodiment, the acceleration program 302 provides LAN-side or
LAN based acceleration or optimization of network traffic.
In some embodiments, the network optimization engine 250 may be
designed, constructed or configured to work with WAN optimization
appliance 200. In other embodiments, network optimization engine
250 may be designed, constructed or configured to provide the WAN
optimization techniques of appliance 200, with or without an
appliance 200. For example, in one embodiment of a WANScaler
appliance 200 manufactured by Citrix Systems, Inc. the network
optimization engine 250 includes the WANscaler client. In some
embodiments, the network optimization engine 250 provides WANScaler
acceleration techniques stand-alone in a remote location, such as a
branch office. In other embodiments, the network optimization
engine 250 works in conjunction with one or more WANScaler
appliances 200.
In another embodiment, the network optimization engine 250 includes
the acceleration program 302, or the function, operations and logic
of the acceleration program 302. In some embodiments, the
acceleration program 302 includes the network optimization engine
250 or the function, operations and logic of the network
optimization engine 250. In yet another embodiment, the network
optimization engine 250 is provided or installed as a separate
program or set of executable instructions from the acceleration
program 302. In other embodiments, the network optimization engine
250 and acceleration program 302 are included in the same program
or same set of executable instructions.
In some embodiments and still referring to FIG. 3, a first program
322 may be used to install and/or execute the client agent 120, or
any portion thereof, automatically, silently, transparently, or
otherwise. In one embodiment, the first program 322 is a plugin
component, such an ActiveX control or Java control or script that
is loaded into and executed by an application. For example, the
first program comprises an ActiveX control loaded and run by a web
browser application, such as in the memory space or context of the
application. In another embodiment, the first program 322 comprises
a set of executable instructions loaded into and run by the
application, such as a browser. In one embodiment, the first
program 322 is designed and constructed program to install the
client agent 120. In some embodiments, the first program 322
obtains, downloads, or receives the client agent 120 via the
network from another computing device. In another embodiment, the
first program 322 is an installer program or a plug and play
manager for installing programs, such as network drivers and the
client agent 120, or any portion thereof, on the operating system
of the client 102.
In some embodiments, each or any of the portions of the client
agent 120--a streaming client 306, a collection agent 304, SSL VPN
agent 308, a network optimization engine 250, acceleration program
302, and interceptor 350--may be installed, executed, configured or
operated as a separate application, program, process, service, task
or set of executable instructions. In other embodiments, each or
any of the portions of the client agent 120 may be installed,
executed, configured or operated together as a single client agent
120.
D. Systems and Methods for Data Flow Control
Referring now to FIG. 4, some embodiments of a system for efficient
data flow control are illustrated. The illustration shows a flow of
data in a system comprising a sender and an appliance disposed in
the path of the data stream transmitted between the sender and the
receiver. FIG. 4 also illustrates embodiments of a system having an
appliance 200 disposed along a data path between a server and a
receiver, as well as embodiments wherein two or more appliances are
deployed along the same data path.
In a brief overview, FIG. 4 illustrates a sender sending data to a
receiver. Since data may be upstream and downstream, both, the
sender or the receiver may either be a client 102 or a server 106.
In some embodiments, the sender or the receiver may be an appliance
200. As shown in FIG. 4, the sender may include an application 405
comprising a data generator 415. Either the application 405 or the
data generator 415 may generate data, such as interactive data 410
or bulk data 411. Herein, interactive data 410 and bulk data 411
may also be referred to as data portions 410 and 411. FIG. 4
illustrates the interactive data 410 and the bulk data 411 flowing
into a network optimizer 420. The network optimizer 420 may include
a data transfer manager 430 and a data transfer model 440. The
network optimizer 420, in a plurality of embodiments, processes the
data and may manage, control or improve the process of sending
data. FIG. 4 also depicts the data portions 410 and 411 formed into
data packets 480A-N and sent over the network from the 466A port of
the sender to the 266A port of the appliance 200. The appliance
200, in addition to the aforementioned packet processing engine
240, the flow controller 220 and the compression engine 238 may
also comprise an intermediary model 455 and a bandwidth measurer
450. In some embodiments, the appliance 200 processes data packets
480 and formats the packets into compressed data packets 495 which
are sent over the network to the receiver.
In the embodiments depicted by FIG. 4, the sender is shown as an
appliance comprising a number of components. It should be
understood the sender may be any type of device sending or
receiving communication via a network. In some embodiments, the
sender is any system, apparatus or a unit communicating with
another device. In a number of embodiments, the sender is a device
running an application generating bulk data 411 or data which is
not real time data. In a plurality of embodiments, the sender is a
device running an application generating an interactive data 410 or
a real time data. In some embodiments, the sender comprises a data
generator. In some embodiments, the sender comprises a device, a
unit, a program or a system controlling the flow of information or
data transmitted by the sender. In a plurality of embodiments, the
sender comprises a compression engine or a data formatting unit. In
some embodiments, the sender is a device or a system capable of
transmitting or receiving information or data.
Application 405 may be any application, computer program, firmware
or software running on a sender. In a plurality of embodiments, the
application 405 is a device, system, unit or a software generating
or sending data. Application 405 may comprise a data generator 415
generating interactive data 410 or bulk data 411. In a number of
embodiments, application 405 generates interactive data 410 or bulk
data 411. In specific embodiments, application 405 or data
generator 415 generate a combination of bulk data 411 and
interactive data 410. The data may be generated in a continuous
stream and may be of any format. Sometimes, the data is generated
in discrete steps or in non-continuous way. In some embodiments,
data generated by application 405 includes an action, instruction
or data from the user. Such actions, instructions or data may
comprise a movement of a mouse on a user's computer, a click of a
mouse on a computer, an input from a keyboard, a video or audio
stream, a computer program or an application, a video game or any
kind of software or computer generated data. In some embodiments,
application 405 generates a data such as a display of an action or
a command of the user such as a letter typed by the user in an
application such as a text editor. The application 405 may comprise
any type or form of virtualization application, program, software
or computer service. In some embodiments, the application 405
comprises a remote display application, a remote access application
or a web browser. In a number of embodiments, application 405 is a
computer operating system. In one embodiment, the application is,
comprises or interfaces with an ICA client, developed by Citrix
Systems, Inc. of Fort Lauderdale, Fla. In other embodiments, the
application is, comprises or interfaces with a Remote Desktop (RDP)
client, developed by Microsoft Corporation of Redmond, Wash. In a
plurality of embodiments, application 405 is any type of an editing
application, calculating application, storage application, planning
application, graphical or a video application, audio application,
an instant messenger application or any other type of application
which may be run on a client 102, a server 106 or otherwise to
produce or generate data.
In some embodiments, the application uses a protocol having
multiple channels for communicating bulk and interactive data. A
communication channel may be any medium, path or means of
communication used for a particular type of transmission or data.
In some embodiments, communication channels may be used for
transmitting multiple kinds of data. Sometimes, channels are
defined by a communication protocol used for communication. In one
embodiment, one or more channels are used for communicating
interactive data. In some embodiments, one or more channels are
used for communicating bulk data. In some embodiments, one or more
channels are used for interactive data while one or more other
channels are used for bulk data. In yet another embodiments, a
single communication channel may be used for communicating bulk
data and interactive data. In one embodiment, the channels of
communication are established and maintained by a protocol of an
ICA client or a Remote Desktop Client protocol.
Data generator 415 may be any application, software, hardware,
device or a unit generating or producing data. Though, as
illustrated by FIG. 4, data generator 415 may be comprised or
controlled by the application 405, data generator 415 may also be a
standalone, independent unit operating and producing data. Data
generator 415 may comprise any type and form of software,
application service, library, database, process, task or set of
executable instructions. In a plurality of embodiments, data
generator 415 is a component managing data generated by another
application or a software. In some embodiments, data generator 415
is a unit or a system processing, preparing, formatting or shaping
the data generated by an application for network optimizer. In a
number of embodiments, data generator 415 operates as an
intermediate step or an interface for the data outputted by the
application 405. Data generator 415 may prepare, format or process
the data and interface with network optimizer 420. In some
embodiments, data generator 415 is a software component managing or
transforming the data created by the application 405.
Data generator 415 may generate any type of data, code, instruction
or communication. In some embodiments, data generator 415 generates
interactive data 410. In some embodiments, data generator 415
generates bulk data 411. Data generator 415 may generate any
combination of interactive and bulk data in any format. Data
generator 415 may be a component of a software or an application
producing data of any kind. Data generator 415 may be a unit
producing an output, such as a video or graphical output.
Sometimes, data generator may produce an output for a graphical
user interface.
Interactive data 410 may be any type of data resulting from
interaction between one device and another device. Interactive data
410 may be any kind of real-time data. Interactive data 410 may
also be any data that updates on its own schedule, such as stock
quotes, manufacturing statistics, web server loads, warehouse
activity, traffic and more. Sometimes, interactive data 410 may be
any type and form of data resulting from user interaction with a
client 102, server 106, intermediary appliance 200 or any other
device on a network 104. In some embodiment, interactive data 410
is output from an application, such as display output, for example,
display output transmitted via remote display protocol. In some
embodiments, interactive data 410 is data resulting from a computer
mouse or an input on a computer. In a plurality of embodiments,
interactive data 410 is a letter, character or a symbol typed in
from the keyboard of a computer. In a number of embodiments,
interactive data 410 is a continuously updating data stream from an
application 405 or a data generator 415. In a plurality of
embodiments, interactive data 410 is related to any data produced
by the application, by the user or by the sender. In some
embodiments, interactive data 410 is a constantly changing data
while in other embodiments 410 interactive data does not have to be
constantly changing. In a number of embodiments, interactive data
410 comprises a component of data which is not changing. In some
embodiments, interactive data 410 comprises any type of data that
may have a varying time of data generated. In a number of
embodiments, interactive data 410 is generated within a periodic
and predefined generation time which may be constant or may be
changing. Interactive data 410 may be any data whose transfer in a
remote desktop application from a server to a client is of a higher
priority than other type of data whose transfer at a later time
will not impact the quality of user experience.
In a plurality of embodiments, interactive data 410 is user input
dependent. In certain embodiments, interactive data 410 has a
periodic generation time wherein a period of time in which an
amount of data is generated varies in duration from another period
of time in which another amount of data is generated. In a number
of embodiments, interactive data 410 is generated in a continuous
or a discrete fashion in which each discrete amount of time within
which an amount of data is generated may have a different amount of
data generated from another amount of data generated in another
discrete amount of time. In some embodiments, interactive data 410
comprises a data stream. In a plurality of embodiments, interactive
data 410 comprises a user data or a payload. In a plurality of
embodiments, interactive data 410 comprises a frame or a screen
shot of an application as displayed on the screen of a
computer.
Bulk data 411 may be any type of data having less of a priority to
be transferred than interactive data. Bulk data 411 may be any data
not being subject to change over a longer period of time than the
period of time within which interactive data 410 is going to
change. Bulk data 411 may be data comprising information regarding
files to be printed. Bulk data 411 may be data comprising a large
chunk or a large size of data whose transfer is at a lower priority
than the transfer of the interactive data 410. In some embodiments,
bulk data 411 comprises an amount of data greater than a
predetermined threshold. In many embodiments, bulk data 411 is any
type of non real-time data. In some embodiments, bulk data 411
comprises commands, data or instructions for printing a file or a
program. In a number of embodiments, bulk data 411 comprises any
data including components of data that are unchanging or remaining
constant over a relatively short or a relatively long period of
time. In some embodiments, bulk data 411 comprises portions of data
that are changing or do not remain constant over a relatively short
or a relatively long period of time. In a plurality of embodiments,
bulk data 411 comprises a file, a video, an audio, an application,
or data from a data base. In some embodiments, bulk data 411
comprises elements of a graphical user interface. In a plurality of
embodiments, bulk data 411 comprises a user data or a payload.
Network optimizer 420 may be any type of a device, structure or an
application which improves, controls, manages or optimizes a flow
of data. Network optimizer 420 may be a system or a unit
controlling and managing the flow of data transferred between the
sender and a receiver. A network optimizer 420 may be any
component, unit or a system receiving interactive data 410 and bulk
data 411 and controlling the output flow of the interactive data
410 and the bulk data 411 from the sender to the receiver. Network
optimizer 420 may be any component, a function or a unit,
comprising any hardware, software, circuitry or logic for forming,
formatting, managing and controlling the flow of data transmitted
by the sender. The network optimizer 420 may be any device,
application or a unit distinguishing between bulk data 411 and
interactive data 410. Network optimizer 420 may separate or sort
the real time data from the interactive data in order to manage or
control the transfer of the data. In one embodiment, network
optimizer 420 identifies bulk data from the interactive data and
formats or sorts the bulk data and interactive data in their
respective packets based on their identification. In another
embodiment, the network optimizer 420 processes data generated by
the application 405 or the data generator 415 in order to control
the amount of bulk data 411 and interactive data 410 to be
transmitted over the network. Network optimizer 420 may comprise a
model used for transmission of the interactive data 410 and bulk
data 411 over the network to the receiver. The model may comprise
any type of statistics used for anticipating or estimating a more
or the most efficient amount of data to be transmitted over the
network. In some embodiments, network optimizer 420 comprises a
data transfer model which comprises information relating the data
congestion and data occupancy on the network. The network optimizer
may assist the data transfer manager in selecting an optimal or
desired amount of data to be sent over the network and/or timing of
the data to be sent over the network. In a number of embodiments,
network optimizer reorganizes or reformats data in data packets
480. The network optimizer comprises the network optimization
engine or any portion thereof.
Network optimizer 420 may comprise a model for managing or
controlling transmission of data to a receiver. The model of the
network optimizer 420 may be any model within the network optimizer
420, such as the data transfer model 440. The model of the network
optimizer 420 may also be interchangeably referred to as the data
transfer model 440 or the sender's model. Network optimizer 420 may
utilize one or more models to control various aspects of the data
or information transmission control, such as amounts of information
to be transmitted, type of information to be transmitted or the
timing of the amounts of information to be transmitted. Sometimes,
one or more models of the network optimizer 420 utilizes statistics
such as bandwidth of the network, congestion of the network or
traffic affecting sender or the receiver, backlog of the
information, and similar in order to determine the amount of data
to be sent to the receiver and the time at which to send the amount
of data. The data or information transmitted to the receiver using
the model may be referred to as the bulk data 411 and/or
interactive data 410.
In many embodiments, the model of the network optimizer 420 is
updated by messages from a model of the appliance 200, such as the
intermediary model 455. The intermediary model 455 of the appliance
200 may include more updated statistics, metrics or values for
determinations of bandwidth between the sender and the receiver,
compression ratio of a data compressed, or a backlog value of an
amount of data to be transmitted. The intermediary model 455 upon
realizing that the more updated determination or estimate of the
value of bandwidth is more accurate than the value of bandwidth of
the model of the network optimizer 420 of the sender, may send to
the sender or to the sender's model the more updated value of
bandwidth, the more updated value of compression ratio of
transmitted data, or the backlog value. In some embodiments, the
intermediary model sends updates of bandwidth values or
measurements as changes occur. In other embodiments, the
intermediary model sends updates of bandwidth values at a
predetermined frequency. In some embodiments, the intermediary
model sends updates of bandwidth values responsive to any type and
form of event. In one embodiment, the intermediary model sends
updates of bandwidth values responsive to a request.
The network optimizer 420 may update the sender's model in response
to the received message comprising the updated values of the
bandwidth from the intermediary model 455. Such updates may enable
the network optimizer 420 to more accurately determine the amount
of bulk data 411 and interactive data 410 to be transmitted and the
timing of the amount of each type of data to be transmitted.
Network optimizer 420 may utilize the data transfer manager 430 to
control the amount and type of data or information to be
transmitted utilizing the data transfer model 440 to determine the
amount and timing of the data to transmit to the receiver via the
appliance 200. Network optimizer 420 may utilize statistics or
values from the model of the network optimizer 420, or from data
transfer model 440, to determine the amount and the timing of
transmission for each one of the interactive data 410 and bulk data
411. Network optimizer 420 may then utilize data transfer manager
430 to execute the transmission using the amount and the timing
determined by the model, such as the data transfer model 440, or
any other model of the network optimizer 420.
Data transfer manager 430 may be any type of device, software,
application or a unit for controlling or managing the transfer or
transmission of data from the sender to the receiver. Data transfer
manager 430 may be a communication device capable of controlling
the amount of transmitted information and the timing of the amount
of the information transmitted. Data transfer manager 420 may be
any device, unit, software or a component of the sender
transmitting information using the values and statistics provided
by any network optimizer 420 model, such as the data transfer model
440. Data transfer manager may comprise any hardware, software,
circuitry, processors, logic and processing circuits, memory,
firmware, logical functions or components to enable control and
management of the data transmitted. Data transfer manager 430 In
some embodiments, a data transfer manager 430 comprises software.
The data transfer manager 430 may comprise any components or
functionality to manage and maintain the backlog of the information
to be transmitted. Data transfer manager 430 may comprise any
features or functionality of a network optimizer 420, flow
controller 220 or a data transfer model 440. In some embodiments,
data transfer manager 430 is combined or fused into a single
device, unit, function, software or a component together with the
network optimizer 420, flow controller 220 and data transfer model
440. In some embodiments, data transfer manager 430 is a part of
the network optimizer 420. In some embodiments, data transfer
manager 430 is not comprised by the network optimizer 420, but
communicates with it. In some embodiments, data transfer manager
430 is a part of the sender, while in other embodiments data
transfer manager 430 is a component separate from the sender.
The network optimizer 420 and data transfer manager 430 may each
comprise the functionality to determine when to transmit data,
messages or information and determine the amount of data, messages
or information to transmit. The network optimizer 420 and transfer
manager 430 may control transmission of the information as
determined as well as the timing of the transmission. The data
transfer manager 430 may prioritize the order, timing and size of
data to transmit. The data transfer manager 430 may distinguish
between bulk and interactive data and manage transmission according
to the amount of each. Sometimes, network optimizer 420 or the data
transfer manager 430 utilize bandwidth estimation from the
bandwidth monitor 720 to determine the amount of data to be
transmitted. Sometimes, network optimizer 420 and data transfer
manager 430 utilize compression statistics from the compression
engine 238 or the backlog value from the appliance 200, or the
intermediary, to determine the amount of data to transmit and the
timing to transmit the data. The backlog of the intermediary 200
may be made up of the data previously transmitted by the sender but
not yet forwarded to the receiver for whatever reason.
Data transfer manager 430 may utilize any statistics or metrics
from any source to execute transmission of the data. In some
embodiments, data transfer manager 430 may use statistics or
metrics, such as the bandwidth information from a bandwidth
monitoring component, internal or external to the sender, in order
to manage the transmission of the data. In some embodiments, a data
transfer manager 430 determines a next amount of the data to be
sent based on the value of bandwidth known to the data transfer
manager 430. In certain embodiments, a data transfer manager 430
determines a timing of the next amount of data to be sent based on
the value of bandwidth known to the data transfer manager 430. In a
plurality of embodiments, a data transfer manager 430 determines a
next amount of the data to be sent or the timing of the next amount
of data to be sent based on the compression ratio of a data
compressed used by appliance 200. In certain embodiments, a data
transfer manager 430 determines a next amount of the data to be
sent or the timing of the next amount of data to be sent based on
backlog information of the data to be transferred backlogged in a
queue or stored in a memory before transmitted to the receiver.
Backlog information may include any type of information, bulk or
interactive data 411 and 410, metrics or statistics on any data
queued to be transmitted or the updated values or messages to be
transmitted between the sender's models, such as the data transfer
model 440 and the receiver's models, such as the intermediary model
455 of the appliance 200 or a model of the receiver receiving the
data from the appliance 200.
Data transfer manager 430 may determine any of: the timing or the
amount of interactive data 410 to be transmitted, the timing or the
amount of bulk data 411 to be transmitted, the amount of data as
well as the specific portion of data to be sent during the next
scheduled data transmitting event or the specific data from the
determined amount to be sent during the next scheduled data
transmitting event. In certain embodiments, the data transfer
manager 430 makes determinations based on a compression ratio value
of a compression ratio of a data compressed by an intermediary or
an appliance 200, a backlog value of an amount of data to be sent
from the appliance 200 to the receiver, or a bandwidth value
expressing the available bandwidth of the network 104.
Data transfer model 440 may be any component or a unit used to
store, represent or maintain a model to determine the amount of
data to be transmitted and the timing of the data to be
transmitted. Data transfer model 440 may be also referred to as the
model of the network optimizer 420 described above. Network
transfer model 420 may comprise a number of models and each of the
models may comprise each and every functionality of the data
transfer model 440 and any model of network optimizer 420 described
above. Data transfer model 440 may comprise a software, an
algorithm, an application, a logic unit, a memory, a processor, a
hardware or any other component enabling the data transfer model
440 to maintain or update the values, metrics or statistics used to
determine the amount and timing of the transmissions by the sender.
The values, metrics or statistics may be values such as the
bandwidth of the network, the compression ratio of a data
compressed by either the sender or the appliance 200, the backlog
value of an amount data backlogged for transmission either by the
sender or by the appliance 200, the bandwidth between the sender
and the appliance 200, the bandwidth between the appliance 200 and
the receiver, the bandwidth between the sender and the receiver via
the appliance 200, and more.
Data transfer model 440 may also receive from either the appliance
200 or the receiver the message which may comprise updated values
of any of the bandwidth, compression ratios or backlog values. Data
transfer model 440 may update the values, metrics or the statistics
with the new received values from the received message. Data
transfer model 440 may transmit messages back and forth with the
model of the appliance or the receiver, such as the intermediary
model 455 for example, in order to exchange the latest values,
metrics and statistics and update the sender's model, such as the
data transfer model 440. The model of the appliance 200, the
intermediary model 455, being more likely to have more updated and
more correct values, may provide the data transfer model 440 the
latest values and statistics enabling the network optimizer 420 or
the data transfer manager 430 to more accurately control the
transmission of the data or information from the sender. Messages
comprising the updated values used by the models may be transmitted
between the sender and the receiver or between the sender and the
intermediary, also referred to as the appliance 200, via data
packets 480 and compressed data packets 495. In some embodiments,
the messages may be transmitted together with interactive data 410
and bulk data 411. Sometimes, the messages may be transmitted
individually and separately from the data or other information
transmitted between the sender and the receiver.
Data transfer model 440 may monitor, estimate and/or predict any of
the statistics affecting the transmission of the information or
data between the sender and the receiver. In some embodiments, data
transfer model 440 may monitor, estimate or predict the congestion
of the network 104, bandwidth utilization or available bandwidth of
the network 104. The data transform model 440 may include any type
and form of model representation, such as data, data structures
and/or executable instructions. Data transfer model 440 may store
the latest statistics and information used to determine the optimal
amount of data or information to be transmitted and optimal timing
to transmit the amount in order to fully utilize available
resources and not create any additional delays by sending too much
data too quickly. Data transfer model 440 may comprise algorithms
to determine the amount of interactive data 411 and bulk data 410
to be transmitted and at what time based on the latest updated
information, values or statistics, as updated by messages received
from the model of the receiver. The receiver, transmitting the
messages comprising the updated values or statistics, may be the
receiver receiving the interactive and bulk data 410 and 411. The
receiver may also be the appliance 200, also referred to as the
intermediary, traversing the data transmitted between the sender
and the receiver. The appliance 200 may comprise the receiver's
model and collect the statistics, such as the bandwidth,
compression ratio of a data compressed or the backlog value to
update the data transfer model 440. In some embodiments, data
transfer model 440 receives messages with updated values or
statistics from the model from the appliance 200 traversing the
information transmitted and from the receiver receiving the
information transmitted. The data transfer model 440 may utilize
messages from both, the model of the appliance 200 and the model of
the receiver, to update the values, metrics and statistics of the
data transfer model 440 with the latest values, metrics or
statistics.
For example, in a system depicted by FIG. 4, a sender may transmit
via the appliance 200 to the receiver data which comprises
interactive data 410 and bulk data 411. The network 104, or a
connection between the sender and the receiver, may support an
optimal amount of transmission which would utilize the available
resources of the network to the maximum but not created additional
delays and backlog. The network optimizer 420 and the data transfer
model 440 may estimate the optimal amount of transmission based on
the data transfer model 440, which may also be referred to as the
model of the network optimizer 420. The data transfer model 440 may
determine the optimal amount of data to be transmitted and the
optimal timing for transmitting the optimal amount of data. The
data transfer model 440 determines the optimal amount and the
optimal timing based on the latest values, metrics and statistics.
The values, metrics and statistics used for determining may be any
information relating the status of the resources on the network,
such as: the bandwidth of the connection between the sender and the
receiver, bandwidth between the sender and the appliance 200,
bandwidth between the appliance 200 and the receiver, mean
bandwidth value between the sender and the receiver, standard
deviation of the bandwidth between any two of the sender, appliance
200 and the receiver, compression ratio of data compressed by the
appliance 200, the backlog value of an amount of data to be
transmitted as stored in the queue of the appliance 200 and the
backlog value of the data to be sent by the sender. The values,
metrics and statistics of the data transfer model 440 may change
with time and thus may become outdated, resulting in the amount of
data to be transmitted and the timing as determined by the model to
be not optimal.
In order to compensate for the outdated values, metrics and
statistics, the intermediary model 455 of the appliance 200 may
transmit to the data transfer model 440 the latest and the most up
to date values, metrics and the statistics via one or more messages
from either the receiver, the appliance 200, or both. The data
transfer model 440 updates the values, metrics and statistics based
on the values, metrics and statistics transmitted within any number
of messages. The messages transmitted between the models may
include any information relating the state of data or state of
resources of the network. The data transfer model 440 may receive
the message with updated metrics, values and statistics and metrics
and may determine the new amount of data to be transmitted and the
new timing of the new amount of data to be transmitted. The new
amount and the new timing are determined using the latest metrics,
values and statistics and are therefore optimal or closer to being
optimal since the information used for determination are more up to
date. Data transfer manager 430, may receive the new amount and the
new timing and may transmit, via the appliance 200 to the receiver,
a new amount of data 410 or 411 as determined by the new amount and
at the time determined by the new timing. The transmission may thus
be optimal until the situation of the network or network resources
changes again. The appliance 200 and the receiver may keep
monitoring the network and keep updating their models as necessary
in order to update the data transfer model 440 for the future
transmissions.
Sometimes, the data transfer model 440 may be used to calculate the
amount of data to be sent over the network and the timing of amount
of data to be transferred. Data transfer model 440 may also be used
to determine which portions of the amount to be transferred will be
made up of interactive data 410 or bulk data 411. In some
embodiments, the data transfer model determines which data to be
transmitted based on the backlog of the data in the queue of the
appliance 200 waiting to be transmitted from the appliance 200 to
the receiver.
FIG. 4 also illustrates communication of data packets 480 between
the sender and a receiver, such as the appliance 200. The data
packets are labeled 480A-N where N may stand for any number or
symbol. Data packets may be any chunks, groups or amounts of data
or information organized using any format utilized by the system.
In some embodiments, data packets 480 are sequences of bytes
comprising a header and a body. In a plurality of embodiments, data
packets 480 comprise an identifier uniquely identifying each data
packet from any other data packet communicated via the system. In a
plurality of embodiments, data packets 480 are used as a part of a
TCP communication. In some embodiments, data packets are compressed
data packers, payloads or groups of information. In certain
embodiments, data packets 480 may comprise packets and/or payloads
of same size. In a plurality of embodiments, a data packet 480A may
have a different size than another data packet 480B. In some
embodiments, a data packet 480 comprises an instruction. In a
plurality of embodiments, a data packet 480 comprises an
information, a value or a data. In some embodiments, a data packet
480 comprises a command. In a number of embodiments, a data packet
480 comprises a user data or a payload. In some embodiments, a data
packet 480 comprises an error detection code or an error detection
mechanism. In a plurality of embodiments, a data packet 480 is a
formatted group of information communicated via a TCP/IP network
communication or any other network communication protocol.
FIG. 4 also illustrates appliance 200, already introduced earlier,
and shown communicating with the sender and another appliance 200,
client 102, or server 106 (e.g., receivers) which receive the
transmission from the sender. In some embodiments, appliance 200
comprises any number of subcomponents introduced earlier, such as
the packet processing engine 240, the flow controller 220 and the
compression engine 238. FIG. 4 illustrates a number of embodiments
wherein the appliance 200 comprises the intermediary model 455 and
the bandwidth measurer 450. In some embodiments, the network system
depicted by FIG. 4 may be such that the speed of the network
transmissions between the sender and the appliance 200 is
substantially faster than the speed of the network transmissions
between the appliance 200 and the receiver, wherein the receiver
may be another appliance 200, a client 102 or a server 106.
Compression engine 238, in addition to aforementioned features and
embodiments, may also comprise other features or embodiments such
as the means to perform high performance network compression. In
some embodiments, compression engine 238 compresses data using a
compression method utilizing a plurality of compressed data packets
wherein one compressed data packet of the plurality of compressed
data packets has a compression ratio different than another
compressed data packet of the plurality of data packets. In a
number of embodiments, a compression engine 238 stores a
compression ratio of each individual compressed packet of a
plurality of packets. In some embodiments, the stored compression
ratio information of each individual compressed data packet is sent
to the sender or the data transfer model 440. In some embodiments,
the compression engine shares information or instructions with
other units or components in the system such as the system
illustrated in FIG. 4 to improve the throughput of the information
or the efficiency of the transmissions. In certain embodiments, the
compression engine 238 is sharing information and communicating
with the sender or some subcomponents or subsystems of the
sender.
The intermediary model 455 may be any device, software, algorithm
or application used to model network activity, bandwidth
utilization, transmission rates and compression rates related to
the intermediary. In one embodiment, the intermediary model may
predict an optimal or desired amount of data to be sent over the
network and the timing of the data to be sent based on a number of
values used for monitoring the state of the network. The
intermediary model 455 may include any type and form of model
representation, such as data, data structures and/or executable
instructions. In a number of embodiments, intermediary model 455 is
an independent device sharing information with appliance 200. In a
plurality of embodiments, intermediary model 455 is a software
application. In certain embodiments, intermediary model 455 is an
appliance. In a plurality of embodiments, intermediary model 455 is
a part of the compression engine 238, and in some other embodiments
the intermediary model 455 comprises the compression engine 238. In
some embodiments, intermediary model 455 is a part of the flow
controller, and in some other embodiments the intermediary model
455 comprises the flow controller.
In some embodiments, intermediary model 455 comprises functions,
operations or logic to model the transmission rates, compression
rates and bandwidth utilization of one or more intermediaries. In
one embodiment, intermediary model 455 is an algorithm using a
statistical approach and a set of most recently updated values to
predict a maximum or otherwise predetermined amount of data that
can be transmitted over the network without creating additional
transmission delays. In some embodiments, intermediary model 455
determines the amount of data to be transmitted over the network
104, such as via the intermediary, and the timing of the data to be
transmitted based on the most recently updated bandwidth value. In
a plurality of embodiments, intermediary model 455 determines the
amount of data to be transmitted over the network 104 and the
timing of the data to be transmitted based on: the most recently
updated compression ratio value of a compressed data packet 495,
compression ratio values of a plurality of compressed data packets
495 or a difference between the compression ratio values of two or
more compressed data packets 495. In some embodiments, intermediary
model 455 determines the amount of data to be transmitted over the
network 104 and the timing of the data to be transmitted based on
the most recently updated backlog value.
Bandwidth measurer 450 may be any bandwidth measuring device,
function, operation or logic for determining bandwidth between two
entities, such as the appliance 200 and a receiver. In some
embodiments, bandwidth measurer 450 performs any type and form of
ping command. In some embodiments, bandwidth measurer 450
determines an availability, idleness, throughput or utilization of
network bandwidth. In another embodiment, bandwidth measurer 450
determines any type of round-trip time between two entities. The
bandwidth measurer 450 may use any type and form of round-trip time
computation or calculation to measure bandwidth. For example, the
measurer 450 may use the following type of bandwidth measurement:
Bandwidth=Factor*MTU/(Round Trip Times*sqrt(Packet Loss)), where
the factor may be for example 1.3 As illustrated by the above
equation, bandwidth may be determined based on packet loss, round
trip times and/or packet size adjusted by a predetermined factor.
Although a measurement of bandwidth using the above equation is
described, other derivatives of this request using any combination
of factors, maximum transmission unit (MTU), round trip times and
packet loss may be used.
In some embodiments, the bandwidth measurer 450 determines a number
of bytes transferred between two entities, such as client and
intermediary, intermediary and server or client and server. The
bandwidth measurer 450 determines the number of transferred bytes
over a time period, such as every second or bytes transferred per
second. In one embodiment, the bandwidth measurer 450 determines an
average number of bytes transferred per the time period, such as
per second. In some embodiments, the bandwidth measurer 450
measures the number of bytes transmitted by the intermediary. In
other embodiments, the bandwidth measurer 450 measures the number
of bytes received by the intermediary. In one embodiment, the
bandwidth measurer 450 measures the number of bytes received and
transmitted by the intermediary. In yet another embodiment, the
bandwidth measurer 450 measures the number of bytes transmitted by
the one or more servers. In other embodiments, the bandwidth
measurer 450 measures the number of bytes transmitted by one or
more clients 102. In other embodiments, the bandwidth measurer 450
measures bandwidth based on the number of packets on a queue
waiting to be transmitted. In some embodiments, the bandwidth
measurer 450 determines bandwidth usage via the transition of a
queue of network packets from empty to non-empty and
vice-versa.
In a number of embodiments, bandwidth measurer 450 measures
bandwidth by a method of bandwidth measurement including the step
of transmitting, from a sender or a receiver, a pair of uniquely
marked data packets 480 or compressed data packets 495 over the
network along with values indicating the time the time of the
transmission of each uniquely marked data packet 480 or compressed
data packet 495. The method of bandwidth measurement also may
comprise the step of receiving the pair of uniquely marked data
packets 480 or compressed data packets 495, transmitted by the
sender or the receiver, and marking the values comprising the
timing of arrival of each data packet 480 or compressed data packet
495 as received by the receiver or the sender. In some embodiments,
the bandwidth measurement method also uses the marked values
indicating the time of the transmission and the values comprising
the timing of arrival to establish the bandwidth of the network. In
a number of embodiments, the method of bandwidth measurement also
subtracts the difference between the timing of arrival of each
uniquely marked data packets 480 or compressed data packets 495
sent using the timing difference between each of the uniquely
marked data packet or compressed data packets received. In a
plurality of embodiments, uniquely marked data packets 480 are
compressed.
In a number of embodiments, a bandwidth measurer 450 comprises an
appliance. In certain embodiments, a bandwidth measurer 450 is a
part of the compression engine 238. In a plurality of embodiments,
a bandwidth measurer 450 is be a part of the flow controller 220.
In some embodiments, a bandwidth measurer 450 is a unit or a device
independent from the network optimization engine 250, while in some
embodiments the bandwidth measurer 450 is a part of the network
optimization engine 250. In a plurality of embodiments, a bandwidth
measurer 450 is a unit or a device independent from the appliance
200. In specific embodiments, bandwidth measurer 450 communicates
the latest or the most recently updated bandwidth value to the
intermediary model 450. In some embodiments, bandwidth measurer 450
communicates the latest or the most recently updated value of the
bandwidth to the sender, the 420 network optimization engine or 440
data transfer model. In a number of embodiments, a bandwidth
measurer 450 uses a plurality of bandwidth determinations to come
up with a bandwidth value which will be used by the intermediary
model 455.
Compressed data packets 495 may be any type and form of compressed
or reformatted groups of data comprising a portion of, one of, or a
plurality of 480 data packets. Compressed data packets 495 comprise
any number of one or more data packets 480. Each of the one or more
compressed data packets may be compressed using the same
compression scheme or different compression scheme. Each of the one
or more compressed data packets may be compressed in a manner
resulting in the same compression ratio or different compression
ratios. In some embodiments, a first compressed data packet 495 out
of a plurality of compressed data packets 495 comprises a number of
data packets 480 different than a number of data packets 480
comprised by a second compressed data packet 495 of a plurality of
compressed data packets 495. In some embodiments, a first
compressed data packet 495 out of a plurality of compressed data
packets 495 comprises a substantially similar number of data
packets 480 in comparison to a number of data packets 480 comprised
by a second compressed data packet 495 of a plurality of compressed
data packets 495. In some embodiments, a first compressed data
packet 495 out of a plurality of compressed data packets 495
comprises a compression ratio that is different than a compression
ratio comprised by a second compressed data packet 495 of a
plurality of compressed data packets 495. In a number of
embodiments, a first compressed data packet 495 out of a plurality
of compressed data packets 495 comprises a compression ratio that
is substantially similar to a compression ratio comprised by a
second compressed data packet 495 of a plurality of compressed data
packets 495.
The receiver is illustrated on the right side of the FIG. 4. The
receiver may be any device, an appliance or any system capable of
receiving information. In some embodiments the receiver is an
appliance 200. In a number of embodiments, the receiver is a client
102. In a plurality of embodiments, the receiver is a server 106.
In a number of embodiments, the receiver may be any combination of
the appliance 200, server 106 or the client 102. The receiver may
comprise any and all of features and embodiments of a server 106, a
client 102 and an appliance 200.
Any embodiment of any feature illustrated in FIG. 4 or in the
description relating to FIG. 4 may be combined with any other
embodiment of any other feature illustrated elsewhere in FIG. 4 or
in the description relating to FIG. 4 or in any other illustration
in the present disclosure or in any portion of the text of the
present disclosure.
Referring now to FIG. 5, an embodiment of steps of a method 500 for
implementing an efficient data flow control by an intermediary
model 455 are illustrated. The steps of the method 500 may be
implemented in any order despite how they are ordered in the
illustration. In some embodiments, some steps of the method 500 are
combined with other steps or may even be omitted from the method.
Furthermore, the decision steps are also presented by the
illustration as a part of the method. The steps are performed by
the system such as the one introduced by FIG. 4, tailored to the
control of the amount of data to transmit by the sender. A number
of embodiments in the method utilize recently updated information
to make a determination of the amount of the data to be transmitted
and the timing of transmission. In some embodiments, the method
utilizes not recently updated information to make a determination
of the amount of the data to be transmitted and the timing of the
transmission.
In brief overview, at step 505 of method 500, a sender transmits to
a first intermediary a first set of values and determinations for
data flow control of the data sent by the sender. At step 510, the
first intermediary establishes a next set of values and
determinations for data flow control of the data sent by the
sender. At step 515, the sender determines if the first set of
values and determinations substantially different from the next set
of values and determinations. At step 520, the sender receives the
next set of values and determinations from the first intermediary.
At step 525, a data transfer manager determines a size of a next
portion of data queued for transmission and a time for transmitting
the portion of data queued.
In further details, step 505 involves a sender transmitting to a
first intermediary a first set of values and determinations for
data flow control of the data sent by the sender. In some
embodiments, the sender in step 505 is the sender described in FIG.
4. The first intermediary described in step 505 may be any device,
system, structure or an appliance intercepting the data transmitted
by the sender to the receiver and performing an operation on the
data transmitted, changing the data transmitted, or affecting the
flow of the data transmitted. In some embodiments, the first
intermediary may be any system, device or a structure intercepting
data between a sender transmitting data and a receiver receiving
the transmitted data. In some embodiments, a first intermediary is
an appliance 200 or appliance 200'.
A first set of values and determinations described in step 505 may
comprise any number of values, constants, functions or data
structures comprising information which may be relevant to the
state of the network or the available resources of the network over
which the data is communicated. These first set of models may be
established or determined via any of the models described herein.
In some embodiments, a first set of values and determinations
comprise a value of a bandwidth between two appliances on a
network. In a number of embodiments, a first set of values and
determinations comprise a value relating a bandwidth determination
of a bandwidth of the network or of the portion of a network over
which the data is communicated. In some embodiments, a first set of
values and determinations comprise a value relating to a
compression of the data being communicated. In a plurality of
embodiments, a first set of values and determinations comprise a
value relating to a compression ratio of the data being transmitted
or communicated. In a number of embodiments, a first set of values
and determinations comprise a value relating to a backlog of the
data transmitted on the network. In some embodiments, a first set
of values and determinations comprise a value relating to specific
time when a next amount of data should be transmitted. In a number
of embodiments, a first set of values and determinations comprise a
value in the form of an integer. In a plurality of embodiments, a
first set of values and determinations comprise a value in the form
of a float, a character or a symbol. In certain embodiments, a
first set of values and determinations comprise an array of values.
In some embodiments, a first set of values and determinations
comprise a data structure comprising a variety of values or arrays
comprising values. In a number of embodiments, a first set of
values and determinations comprise a value relating to a specific
amount of data to be transmitted by the sender or by the first
intermediary, an appliance 200, a client 102 or a server 106. In
some embodiments, a first set of values and determinations comprise
a value relating to an amount of time a next transmission by a
sender, a client 102 or a server 106 should be delay by. In certain
embodiments, a first set of values and determinations is related to
a level of traffic of a network or a congestion of a network over
which the data is transmitted.
At step 510, the first intermediary establishes a next set of
values and determinations for data flow control of the data sent by
the sender. This may be performed via any of the models described
herein. In some embodiments, the first intermediary may be the
first intermediary indicated from step 505. In some embodiments,
the first intermediary may be a different first intermediary having
the same features and embodiments as the first intermediary in step
505. In a plurality of embodiments, a next set of values and
determinations is the first set of values and determinations as
described above. In a number of embodiments, a next set of values
and determinations comprise any and all embodiments of the first
set of values and determinations described above. In some
embodiments, a next set of values and determinations comprise any
and all of features, descriptions, forms as described in the
embodiments of the first set of values and determinations. In a
plurality of embodiments, a next set of values and determinations
is substantially similar in structure and form of the information
comprised to the first set of values and determinations. In a
plurality of embodiments, a next set of values and determinations
is substantially different in structure and form of the information
comprised to the first set of values and determinations. In some
embodiments, the values and determinations comprised in the first
set of values and determinations have a format similar to the one
used in the next set of values and determinations. In some
embodiments, step 510 may occur in response to another step in the
method 500. In some embodiments, step 510 may occur independently
of any other step in the method 500.
At step 515, a decision is made to determine whether or not the
first set of values and determinations is substantially different
from the next set of values and determinations. This may be
performed via any of the models described herein. In a number of
embodiments, step 515 is completed by the sender. In some
embodiments, step 515 is completed by an appliance 200 or a first
intermediary. In some embodiments, "substantially different" in
step 515 indicates anything other than identical from the value
used to be compared to. In a plurality of embodiments,
"substantially different" in step 515 indicates different by more
than a predetermined threshold value from the value being compared
to. In a number of embodiments, "substantially different" in step
515 indicates different as determined by an algorithm or a function
from the value being compared to. In some embodiments,
"substantially different" in step 515 indicates different more than
a predetermined percentage from the value being compared to, or
more than a specific percentage from the average value being
compared to.
In a number of embodiments, a predetermined function, application,
or a value may be established or utilized to help determine what a
substantial difference between two values compared is. This may be
performed via any of the models described herein. In some
embodiments, any difference between a first value of a first set of
values and determinations and a next value, indicating or relating
to a same parameter or feature as the first value of a next set of
values and determinations results in the first set of values and
determinations and the next set of values and determinations being
substantially different. In a plurality of embodiments, a
difference of more than a predetermined value, a predetermined
difference in percentage or a predetermined ratio between a first
value of a first set of values and determinations and a next value,
indicating or relating to a same parameter or feature as the first
value of a next set of values and determinations results in the
first set of values and determinations and the next set of values
and determinations being substantially different. In some
embodiments, step 515 occurs in response to another step in the
method 500. In a number of embodiments, step 515 occurs in response
to either step 505 or step 510, or both step 505 and step 510. In
some embodiments, step 515 occurs independently of any other step
in the method 500.
At step 520, the sender receives the next set of values. This may
be performed using any of the models described herein and sending
and/or receiving any type and form of messages. In some embodiment,
if the result of the step 515 is that the first set of values and
determinations and the next set of values and determinations are
substantially different, the sender receives the next set of values
and determinations from the first intermediary. In some embodiments
the sender receives the next set of values and determinations from
the first intermediary on a regular periodic basis that may be
independent from any other step in the method. In some embodiments,
step 520 may occur in response to the step 515, step 505 or step
510, or in response to a combination of any two or all three of
steps 505, 510 and 515. In some embodiments, step 520 may occur
independently of any other step in the method 500.
At step 525, a data transfer manager determines a size of a next
portion of data queued for transmission and a time for transmitting
the portion of data queued. In some embodiments, the data transfer
manager of step 525 is a data transfer manager 430. In certain
embodiments, a data transfer manager in step 525 may indicate a
data transfer manager in any of the components discussed in FIG. 4.
In a number of embodiments, the size of a next portion of data
queued for transmission and the time for transmitting the portion
of data queued relates to the interactive data 410. In a plurality
of embodiments, the size of a next portion of data queued for
transmission and the time for transmitting the portion of data
queued relates to the bulk data 411. In some embodiments, the size
of a next portion of data queued for transmission and the time for
transmitting the portion of data queued relates to a combination of
the interactive data 410 and the bulk data 411. In certain
embodiments, the size of a next portion of data queued for
transmission and the time for transmitting the portion of data
queued relates to the data sent by a sender, a client 102 or a
server 106 to a first intermediary or an appliance 200. In
plurality of embodiments, the size of a next portion of data queued
for transmission and the time for transmitting the portion of data
queued relates to the data sent by a sender, a client 102 or a
server 106 to a receiver, a client 102 or a server 106.
It should be expressly understood that any embodiment or a feature
illustrated in any figures or in the text relating to any figures
may be combined with any other embodiment or any other feature
illustrated elsewhere in other figures or other portions of the
text.
Referring now to FIG. 6, a number of embodiments of a method 600
for an efficient data flow control by the network optimizer or data
flow manager are illustrated. The steps of the method 600 may be
implemented in any order. In some embodiments, some steps of the
method 600 are combined with other steps or may even be omitted
from the method. Furthermore, the decision steps made by the method
are also illustrated in FIG. 6. The steps may be performed by the
components of a system such as the system presented in FIG. 4,
tailored to the control of the amount of data to transmit by the
sender. FIG. 6 illustrates a number of embodiments wherein the
method utilizes available updated information to make determination
of the amount of the data to be transmitted by the sender and the
timing to transmit the data.
In brief overview, at step 605 of method 600, establishing by the
network optimizer and/or data transfer manager a current threshold
time, a current backlog time, a next frame capture time and a next
threshold time. In a plurality of embodiments, the current
threshold time, the current backlog time, the next frame capture
time and the next threshold time are used for controlling the flow
of data. Sometimes the current threshold time, the current backlog
time, the next frame capture time and the next threshold time are
referred to as method 600 values. The method 600 values may be of
any format or type. In some embodiments, the method 600 values are
integer values. In some embodiments, the method 600 values are
character values, float values or long character values. In a
number of embodiments, the method 600 values are arrays comprising
any number of values of any type. In some embodiments, the method
600 values comprise a data structure comprising any type of values
or arrays. In a plurality of embodiments, the method 600 values are
functions with respect to time or to an event. In a number of
embodiments, the method 600 values may be received from another
component such as an appliance 200, a client 102, server 106, or
any other unit or a system. In some embodiments, the method 600
values may be the first set of values and determinations from
method 500 or the next set of values and determinations from the
method 500. In certain embodiments, the method 600 values may
comprise any and all embodiments or features from the first set of
values and determinations from method 500 or the next set of values
and determinations from the method 500.
Step 610 describes a decision making process wherein the system
answers the question whether the current threshold time is greater
than the current backlog time. In some embodiment, the current
threshold time value is compared to the current backlog time value
using a logic unit such as a logic comparator. In a number of
embodiments, the current threshold time value is compared to the
current backlog time using a microprocessor or a central processing
unit. In a plurality of embodiments, step 610 is performed by a
network optimizer 420, a data transfer manager 430 or a data
transfer model 440. In a number of embodiments, step 610 is
completed by the sender. In some embodiments, step 610 is performed
by an appliance 200 or a first intermediary. In some embodiments,
the comparison in step 610 involves a tolerable range wherein no
action may be taken if the two values are different within the
tolerable range. In a number of embodiments, the tolerable range is
a value or a function of a ratio or a percentage. In some
embodiments, if the result of step 610 is that the current
threshold time is not greater than the current backlog time no
action is taken. In a number of embodiments, if the result of step
610 is that the current threshold time is not greater than the
current backlog time a step 615 is triggered. In some embodiments,
if the result of step 610 is that the current threshold time is
greater than the current backlog time no action is taken. In a
number of embodiments, if the result of step 610 is that the
current threshold time is greater than the current backlog time a
step 615 is triggered. In some embodiments, step 610 occurs in
response to another step in the method 600. In a number of
embodiments, step 610 occurs independently of any other step in the
method 600.
Step 615 describes a decision making process wherein the system
answers the question whether the next frame capture time is less
than the current threshold time plus the next threshold time. In
some embodiments, the current threshold time and the next threshold
time are added before being compared to the next frame capture
time. In some embodiments, the current threshold time and the next
threshold time are not added before being compared to the next
frame capture time. In some embodiments, the comparison in step 615
involves a tolerable range wherein no action may be taken if the
two values are different within the tolerable range. In a number of
embodiments, the tolerable range is a value or a function of a
ratio or a percentage. In some embodiments, if the result of step
615 states that the next frame capture time is less than the
current threshold time plus the next threshold time step 620 is
triggered. In a number of embodiments, if the result of step 615
states that the next frame capture time is less than the current
threshold time plus the next threshold time step 625 is triggered.
In a plurality of embodiments, if the result of step 615 states
that the next frame capture time is equal to or greater than the
current threshold time plus the next threshold time step 620 is
triggered. In some embodiments, if the result of step 615 states
that the next frame capture time is equal to or greater then than
the current threshold time plus the next threshold time step 625 is
triggered. In some embodiments, step 615 occurs in response to
another step in the method 600. In a number of embodiments, step
615 occurs independently of any other step in the method 600.
Step 620 describes selecting an amount of bulk data 411 for
transmission. In some embodiments, a sender may complete step 620.
In a number of embodiments, step 620 is completed by a network
optimizer 420 or a data transfer model 430. In a plurality of
embodiments, an amount of data is determined by a network optimizer
420, a data transfer manager 430 or a data transfer model 440.
Amount of bulk data 411 may be any amount of data expressed in
bytes or any other units. In some embodiments, an amount of bulk
data 411 includes a whole instruction or a task. In a number of
embodiments, an amount of bulk data 411 includes printing
instructions or a file to be printed. In a plurality of
embodiments, an amount of bulk data 411 comprises a graphical
representation of a feature or a shot of a computer screen. In some
embodiments, an amount of bulk data 411 comprises a data file, data
values, instructions, commands, pictures, videos or audio files, or
any other information.
Step 625 recites initiate a next frame capture. In some
embodiments, a sender completes the step 625. In a number of
embodiments, step 625 is completed by a network optimizer 420 or a
data transfer model 430. In a plurality of embodiments, a next
frame capture is initiated by a network optimizer 420 or a data
transfer manager 430. A next frame capture may comprise any amount
of interactive data 410 or bulk data 411. In some embodiments, a
next frame capture comprises any amount of interactive data 411
determined by system. In a plurality of embodiments, a next frame
capture comprises a predetermined set of data planned for
transmission on the next available opportunity.
Any of the embodiments of methods depicted in FIGS. 5 and 6 may
have any of the steps performed via sending of message and updated
values between models.
E. Allocation of Bandwidth
Referring now to FIG. 7, a block diagram is illustrated showing
embodiments of a system for allocation of bandwidth credit by an
intermediary 200. The illustration shows data transmitted from a
sender to a receiver, via an intermediary 200, which may also be
referred to as an appliance 200. The sender and the receiver may
either be a client 102 or a server 106. The intermediary 200
intercepts the data between the sender and the receiver, the data
being presented by data packets 480 and compressed data packets
495. The intermediary 200 may compress data packets 480 sent by the
sender into compressed data packets 495 transmitted to the receiver
using any compression methods or any compression ratios. FIG. 7
illustrates embodiments utilizing only one appliance 200 deployed
between the sender and the receiver although in many applications,
there may be a plurality of appliances 200 deployed between the
sender and the receiver.
In a brief overview, FIG. 7 illustrates a sender sending data to a
receiver via an intermediary 200. In some embodiments, data
transmitted by the sender may be organized into the data packets
480. In some embodiments, the data transmitted by the sender may
comprise data packets 480 along with other additional data formed
or organized in ways other than data packets 480. In many
embodiments, data packets 480 may define any data transmitted by
the sender. The data packets 480 may be received by the
intermediary 200. In addition to the aforementioned flow controller
220, compression engine 238 and bandwidth measurer 450, the
appliance 200 may further comprise a bandwidth allocator 710 and a
bandwidth monitor 720. The intermediary 200 may compress the data
from the sender into compressed data packets 495. The compressed
data packets 495 may be sent or transmitted to the receiver or a
plurality of receivers. The receiver, or the plurality of
receivers, may be any number of clients 102, servers 106,
appliances 200, any of which may receive compressed data packets
495 compressed by the appliance 200.
In many embodiments, the sender may generate data and transmit the
generated data in the form of a stream of data packets 480. In some
embodiments, the sender may receive data from another sender and
forward the data to the appliance 200. The sender may communicate
with the application 200 transmitting the information back and
forth. The information transmitted may comprising data packets 480.
Data packets 480, in some embodiments, further comprise any number
of signals, instructions, digital or analog data, digital data
bits, electrical signals, optical signals, optical pulses, or any
signals detectable by the sender or the receiver.
The appliance 200 illustrated in FIG. 7 may comprise a flow
controller 220. The flow controller 220 may determine the rate of
transmission of the data transmitted by the sender or the receiver.
In a number of embodiments, the flow controller 220 determines the
bandwidth usage of the sender or the receiver. In many embodiments,
the flow controller 220 determines the bandwidth credit of the
sender or the receiver. The flow controller 220 may also determine
a difference between the rate of transmission of the sender or the
receiver and the bandwidth usage of the sender or the receiver. The
flow controller 220 may also determine a difference between the
rate of transmission of the sender or the receiver to determine a
bandwidth credit for the sender or the receiver. In a number of
embodiments, the flow controller 220 determines that a difference
between the rate of transmission of the sender and the bandwidth
usage of the sender falls below or above a predetermined threshold
of the bandwidth credit. In some embodiments, the flow controller
220 determines that a difference between the rate of transmission
of the sender and the bandwidth usage of the sender falls within a
predetermined threshold range.
The bandwidth credit may be any amount of data a sender may
transmit. In some embodiments, the bandwidth credit may be an
amount of bytes, megabytes, gigabytes or terabytes of data a sender
may transmit over a period of time. In a number of embodiments, the
bandwidth credit may be any amount of data a receiver may receive
over a period of time. In some embodiments, the bandwidth credit of
a sender or a receiver is not bounded by a period of time.
Sometimes, a bandwidth credit is an amount of data, in bytes or
megabytes for example, which a sender may send in a one-time
transmission. In some embodiments, a bandwidth credit is an amount
of data in any units of data a sender may transmit in any number of
transmissions. Bandwidth credit, in some embodiments, may be an
amount of bandwidth a sender, an appliance or a receiver may
receive or transmit over a predetermined time period, or even
sometimes independent from any time period.
The compression engine 238, illustrated by FIG. 7, may perform any
compression of data or reformatting of data which traverses the
appliance 200. In some embodiments, the compression engine 238
compresses the data of the appliance 200 using compression ratios
which vary between from a sections of a data stream to a section of
a data stream. For example, some groups of data packets 480 may be
compressed using a compression ratio different from the compression
ratios of other groups of data packets 480. In some embodiments,
compression engine 238 comprises any functionality of a flow
controller 220, a bandwidth measurer 450, or any other
functionality of an appliance 200. In a number of embodiments, the
compression engine 238 compresses the data transmitted by a sender
using a specific compression ratio or a specific compression
format. Sometimes, the compression format or the compression ratio
used by the compression engine 238 is identified by the sender. In
some embodiments, the appliance 200 or the compression engine 238
assigns a compression ratio used for compressing data transmitted
by the sender based on identification of the sender. The
compression engine 238 may compress data transmitted by the sender
or the receiver by using an algorithm compressing data packets 480
from the sender into compressed data packets 495. Some compressed
data packets 495 compressed by the compression engine 238 may have
compression ratios different from the compression ratios of other
compressed data packets 495 compressed by the compression engine
238. Compression engine 238, in some embodiments, monitors the
compression ratios of each compressed data packets 495 and data
packets 480. In some embodiments, the compression engine 238
maintains statistics relating the ratio of size of data packets 480
and compressed data packets 495 or compression ratios relating each
of the data packets 480 or compressed data packets 495.
Bandwidth measurer 450, illustrated by FIG. 7, may be any device,
unit or a function measuring bandwidth between any devices on a
network 104, such as senders, receivers or appliances 200. In many
embodiments, the bandwidth measurer monitors the bandwidth of the
network 104 or over a portion of the network 104. In some
embodiments, bandwidth measurer 450 measures the bandwidth between
two or more appliances, senders or receivers on a network 104. In a
number of embodiments, bandwidth measurer 450 measures the
bandwidth between a sender and an appliance 200. In many
embodiments, the bandwidth measurer 450 measures the bandwidth
between the receiver and the appliance 200. The bandwidth 450 may
measure the bandwidth between two or more appliances, clients or
servers on the network, in the upload or the download directions
separately. In some embodiments, bandwidth measurer 450 measures an
average bandwidth usage over a period of time between a sender and
an appliance 200. In many embodiments, bandwidth measurer 450
measures the amount of data transmitted between two devices on a
network and determines the bandwidth between the two devices using
the amount of the data transmitted and the amount of time it took
to transmit the data. The bandwidth measurer 450 may measure an
average bandwidth credit used by a sender or a receiver over a
period of time. The bandwidth measurer 450 may also measure an
average bandwidth usage over a period of time between a receiver
and an appliance 200. The bandwidth measurer 450 may also measure
an average bandwidth credit for a sender or a receiver unbounded by
or independent from any period of time the bandwidth credit is to
be used for. The average bandwidth usage may be updated after each
period of time passes, thus keeping the average bandwidth usage
updated. In some embodiments, the bandwidth measurer may measure
the available bandwidth or the bandwidth unused by traffic, between
any one of a sender and a receiver, sender and an appliance 200 or
an appliance 200 and a receiver, or any other device or a group of
devices on a network.
Bandwidth allocator 710 may be any device, function, component or
unit for allocating bandwidth or establishing a bandwidth for any
entity or device such as a sender, a receiver or an appliance 200.
The bandwidth allocation may be in a form of a credit, subscription
or annuity of bandwidth allocation in any type and form of units.
Bandwidth allocator 710 may comprise any circuitry, software,
algorithms, functions or devices for determining an amount of
bandwidth to be allocated to any one of a sender, receiver or an
appliance 200. Bandwidth allocator 710 may comprise any type and
form of software, application, library, service, script, process,
task or set of executable instructions. In many embodiments,
bandwidth allocator 710 comprises any functionality of a bandwidth
measurer 450. In some embodiments, bandwidth allocator 710
comprises a bandwidth measurer 450. In some embodiments, bandwidth
measurer 450 comprises a bandwidth allocator 710 or comprises any
functionality of a bandwidth allocator 710.
In some embodiments, bandwidth allocator 710 receives information
relating to bandwidth measurement from a bandwidth measurer and
allocates bandwidth in response to the received information. In a
number of embodiments, bandwidth allocator receives information
from a flow controller 220, compression engine 238, bandwidth
monitor 720, a sender, a receiver or an appliance 220 and
determines an amount of bandwidth to be allocated in response to
the received information. In a variety of embodiments, bandwidth
allocator 710 determines or establishes an amount of bandwidth to
be allocated to any one of a sender, receiver or an appliance 200
using bandwidth statistics or bandwidth measurements, or any
bandwidth related information from any one of bandwidth measurer
450, bandwidth monitor 720, flow controller 220 or any other
component of an appliance 200. In a number of embodiments,
bandwidth allocator 710 determines or establishes an amount of
bandwidth to be allocated to any one of a sender, receiver or an
appliance 200 using bandwidth statistics or bandwidth measurements
or any bandwidth related information from a sender or a receiver.
In some embodiments, bandwidth allocator 710 uses bandwidth usage
statistics or measurements to allocate the bandwidth to any one of
a sender a receiver or an appliance 200. In a plurality of
embodiments, bandwidth allocator 710 allocates a bandwidth amount
to a sender wherein the sender can transmit an amount of
information or data identified by the bandwidth allocated within a
specified amount of time. In some embodiments, bandwidth allocator
710 allocates a bandwidth amount to a sender to transmit an amount
of information or data identified by the bandwidth allocated
regardless of the timing of the transmission. In some embodiments,
the bandwidth allocated by the bandwidth allocator 710 may be used
by the sender to send a one time transmission whose bandwidth
amount does not exceed the amount defined by the bandwidth
allocated. In some embodiments, the bandwidth allocated by the
bandwidth allocator 710 may be used by the sender to send a
plurality of transmissions which use bandwidth amounts equal to or
less than the allocated bandwidth amount.
Bandwidth monitor 720 may be any device, function, component, unit
or piece of software or hardware monitoring bandwidth between any
two or more devices, such as senders, receivers and appliances 200,
on a network. In some embodiments, bandwidth monitor 720 comprises
any circuitry, logic components, hardware, software or a
combination of software and hardware for monitoring bandwidth on a
network. Bandwidth monitor 720 710 may comprise any type and form
of software, application, library, service, script, process, task
or set of executable instructions. In some embodiments, bandwidth
monitor comprises any one of, or any combination of a flow
controller 220, compression engine 238, bandwidth measurer 450 and
bandwidth allocator 710. In a number of embodiments, bandwidth
monitor 720 comprises any functionality of any one or any
combination of a bandwidth allocator 710, bandwidth measurer 450,
compression engine 238 and a flow controller 220. In some
embodiments, any one of a flow controller 220, compression engine
238, bandwidth measurer 450, bandwidth allocator 710 or bandwidth
monitor 720 comprises any functionality, any features or any
processes and functions of any one of, or any combination of a flow
controller 220, compression engine 238, bandwidth measurer 450,
bandwidth allocator 710, bandwidth monitor 720, appliance 200,
sender and a receiver.
In some embodiments, bandwidth monitor 720 monitors bandwidth
between a sender and an appliance 200 by measuring an amount of
bandwidth used between the sender and the appliance 200. In some
embodiments, bandwidth monitor 720 monitors bandwidth between a
receiver and an appliance 200 by measuring an amount of bandwidth
between the sender and the appliance. In a number of embodiments,
bandwidth monitor 720 receives any number of signals or an inputs
from any one of or any combination of: bandwidth measurer 450,
bandwidth allocator 710, compression engine 238, flow controller
220, a sender, an appliance 200 or a receiver, and using the
signals or inputs the bandwidth monitor 720 monitors the bandwidth.
In some embodiments, the bandwidth monitor 720 monitors the
bandwidth between a sender and a client, sender and a receiver or
receiver and a client using a bandwidth measurement or a plurality
of bandwidth measurements from any one of a bandwidth measurer 450,
bandwidth allocator 710 or appliance 200.
In some embodiments, the bandwidth monitor 720 monitors any type of
bandwidth activity via one or more bandwidth measurers 450. The
bandwidth monitor 720 may interface to or communicate with a
bandwidth measurer to obtain measures of bandwidth on a
predetermined frequency, over predetermined time periods, ad-hoc or
upon request. The bandwidth monitor may use any type and form of
API to receive events, updates or information regarding a
measurement of bandwidth performed by a bandwidth measurer. The
bandwidth monitor 720 may monitor an amount of bandwidth used in
relation to a bandwidth allocation to an entity such as a client.
The bandwidth monitor 720 may monitor an amount of bandwidth used
in relation to a bandwidth credit, subscription or annuity of an
entity such as a client.
Referring now to FIG. 8, an embodiment of steps of a method 800 for
allocating a bandwidth credit is illustrated. In some aspects, the
method 800 comprises steps for allocating a bandwidth credit to an
entity, such as a sender or a receiver. In many embodiments, an
intermediary deployed between a sender and one or more receivers
allocates a bandwidth credit of the sender or the receiver by
comparing the allocated bandwidth credit to a measurement of data
transmission rate. In some aspects, some steps of method 800 recite
renewing an annuity of bandwidth credit of a sender or a receiver.
In many embodiments, an intermediary deployed between a sender and
one or more receivers renews an annuity of bandwidth credit of the
sender by determining the allocated bandwidth credit to a
measurement of data transmission rate. In addition, the method 800
may comprise any additional steps which may be implemented in any
order.
FIG. 8 illustrates an embodiment of a method 800 comprising steps
805 through 840. At step 805, a bandwidth credit is allocated to a
sender. In some embodiments, at Step 810 an annuity of bandwidth
credit is allocated to the sender. At step 815, bandwidth usage is
monitored by determining a ratio of compression and a rate of
transmission. At step 820, monitoring bandwidth usage of the sender
over the predetermined annuity period. At step 825, a difference
between the rate of transmission of the sender and the bandwidth
usage of the sender is determined to fall below a predetermined
threshold of the bandwidth credit. In some embodiments, at step
830, a difference between the bandwidth usage of the sender over
the annuity period and the annuity of bandwidth credit is
determined to exceed a predetermined threshold. At step 835 in
response to the determination at step 825, an allocation of a
one-time bandwidth credit is communicated to the sender, such as
based on the difference. At step 840, in response to the
determination at step 830, a renewed allocation of the annuity
bandwidth credit is communicated to the sender based on a second
predetermined ratio of compression.
In further detail of step 805, any type and form of bandwidth
credit may be allocated to an entity, such as a sender. In some
embodiments, an intermediary 200, allocates a bandwidth credit to a
sender, a receiver, or even an intermediary 200. Sometimes, a
bandwidth allocator 710 may allocate a bandwidth credit to a sender
or a receiver. In many embodiments, a bandwidth credit allocated
identifies an amount of data the sender may transmit over a
predetermined period of time. In some embodiments, a bandwidth
credit allocated identifies an amount of data the sender may
transmit to one or more receivers. In a number of embodiments, the
bandwidth credit allocated identifies an amount of data the sender
may transmit to a receiver via an intermediary. In a variety of
embodiments, the bandwidth credit allocated identifies an amount of
data of the sender compressed by the intermediary and transmitted
to the receiver. In some embodiments, a bandwidth credit is
allocated by comparing a bandwidth credit determined to a
measurement of data transmission rate between a sender and an
intermediary 200. Sometimes, a bandwidth credit is allocated by
comparing a bandwidth credit determined to a measurement of data
transmission rate between a receiver and an intermediary 200. In
many embodiments, a bandwidth credit to the sender or the receiver
is allocated by comparing a bandwidth credit determined to a
measurement of data transmission rate traversing an intermediary.
In many embodiments, allocating a bandwidth credit to the sender or
the receiver is completed using a determination of the compression
of data of the sender compressed by the intermediary 200 or using a
compression ratio of the data of the sender compressed by the
intermediary 200. In a number of embodiments, a bandwidth credit is
allocated using a determination of the compression of data of the
receiver compressed by the intermediary 200, or using a compression
ratio of the data of the sender compressed by the intermediary
200.
In some embodiments, a plurality of bandwidth credits may be
allocated to a plurality of senders. Each of the plurality of
bandwidth credits may correspond to each one of the senders and
identifying an amount of data each of the plurality of senders may
transmit to one or more receivers. In some embodiments, allocating
a bandwidth credit to a sender comprises identification of an
amount of data the sender may transmit in a one-time transmission
to a receiver. In a number of embodiments, allocating a bandwidth
credit to a sender comprises an identification of an amount of data
the sender may transmit to a receiver over a plurality of
transmissions within a predetermined period of time. In a plurality
of embodiments, allocating a bandwidth credit to a sender comprises
an identification of an amount of data the sender may transmit to a
receiver over a plurality of transmissions not bounded by any
period of time. Sometimes, allocating a bandwidth credit to a
sender comprises an identification of an amount of data the sender
may transmit to a receiver via an intermediary 200. In some
embodiments, allocating a bandwidth credit to a sender comprises an
identification of specific data the sender may transmit to a
receiver. In a number of embodiments, an identification of an
amount of data the sender may transmit to a receiver is responsive
to an information relating the compression ratios of the data of
the sender transmitted to the receiver and compressed by the
intermediary.
At step 810, any type and form of annuity of bandwidth credit may
be allocated to an entity, such as a sender. In some embodiments,
an intermediary 200 allocates an annuity of bandwidth credit to a
sender or a receiver. In a number of embodiments, a bandwidth
allocator 710 allocates an annuity of bandwidth credit to a sender
or a receiver. In many embodiments, an annuity of bandwidth credit
allocated identifies an amount of data the sender may transmit over
a predetermined period of time, such as every day, week, month,
year or any other annuity period. In some embodiments, an annuity
of bandwidth credit allocated identifies an amount of data the
sender may transmit to one or more receivers. In a number of
embodiments, the annuity of bandwidth credit allocated identifies
an amount of data the sender may transmit to a receiver via an
intermediary over the annuity period. In a variety of embodiments,
the annuity of bandwidth credit allocated identifies an amount of
data of the sender compressed by the intermediary and transmitted
to the receiver over the annuity period. In some embodiments, an
annuity of bandwidth credit of the sender or the receiver is
allocated using an amount of bandwidth determined by an appliance
200 or bandwidth allocator 710. In a number of embodiments, an
annuity of bandwidth credit is allocated by utilizing a
determination of a data transmission rate of the data sent by the
sender. In a number of embodiments, an annuity of bandwidth credit
is allocated by utilizing a determination of a data transmission
rate of the data sent by the receiver. In some embodiments, an
annuity of bandwidth credit is allocated by using a determination
of compression or compression ratio of data transmitted by the
sender. Sometimes, an annuity of bandwidth credit is allocated by
using a determination of compression or compression ratio of data
transmitted by the receiver.
In some embodiments, a plurality of annuities of bandwidth credits
are allocated to or for a plurality of senders. Each of the
plurality of annuities of bandwidth credits may correspond to each
one of the senders, identifying an amount of data each of the
plurality of senders may transmit to one or more receivers. In some
embodiments, allocating an annuity of bandwidth credit to a sender,
or a receiver, comprises identification of an amount of data the
sender or the receiver may transmit in a one-time transmission. In
a number of embodiments, allocating an annuity of bandwidth credit
comprises an identification of an amount of data the sender may
transmit to a receiver over a plurality of transmissions within a
predetermined period of time. In a plurality of embodiments,
allocating an annuity of bandwidth credit to a sender comprises an
identification of an amount of data the sender may transmit to a
receiver over a plurality of transmissions not bounded by any
period of time. Sometimes, allocating an annuity of bandwidth
credit to a sender comprises an identification of an amount of data
the sender may transmit to a receiver via an intermediary 200. In
some embodiments, allocating an annuity of bandwidth credit to a
sender comprises an identification of specific data the sender may
transmit to a receiver. In a number of embodiments, an
identification of an amount of data the sender may transmit to a
receiver is responsive to an information relating the compression
ratios of the data of the sender transmitted to the receiver and
compressed by the intermediary. In some embodiments, an
identification of an amount of data the sender may transmit to a
receiver is responsive to a determination of data transmission rate
of either a sender or a receiver.
At step 815, bandwidth usage is monitored, for example, by
determining a ratio of compression and a rate of transmission. In
some embodiments, a bandwidth monitor 720 monitors the bandwidth
usage. In a number of the embodiments, the bandwidth usage
monitored is the bandwidth usage of the sender. Sometimes, the
bandwidth usage monitored may be the bandwidth usage of the
receiver. In some embodiments, the bandwidth usage monitored is the
bandwidth usage of the sender or the receiver traversing an
intermediary 200. In a plurality of embodiments, bandwidth usage is
monitored by determining a ratio of compression of data of the
sender compressed by the intermediary. In many embodiments,
bandwidth usage is monitored by determining a rate of transmission
of data by the sender compressed by the intermediary. In some
embodiments, bandwidth usage is monitored by determining a ratio of
compression of data of the receiver compressed by the intermediary.
In many embodiments, bandwidth usage is monitored by determining a
rate of transmission of data by the receiver compressed by the
intermediary. In some embodiments, bandwidth usage is monitored by
determining a ratio of compression of data of the receiver or the
sender traversing an intermediary within a predetermined amount of
time. In many embodiments, the ratio of compression of data of the
receiver or the sender is determined by determining an average of a
compression of data compressed by the intermediary over a
predetermined period of time. In many embodiments, the ratio of
compression of data of the receiver or the sender is determined by
determining a median of a compression of data compressed by the
intermediary over a predetermined period of time. In many
embodiments, the rate of transmission of compressed data is
determined by establishing or estimating an average rate of
transmission of compressed data over a predetermined period of
time. In many embodiments, the rate of transmission of compressed
data is determined by establishing or estimating a median rate of
transmission of compressed data over a predetermined period of
time. In some embodiments, bandwidth usage is monitored by
determining a ratio of compression data of the sender compressed by
the intermediary and a rate of transmission of compressed data of
the sender transmitted by the intermediary to one or more
receivers. In a variety of embodiments, bandwidth usage is
monitored by measuring or monitoring bandwidth usage by any one of,
or any combination of: a sender transmitting the data, the sender
receiving the data, an appliance 200 receiving the data, the
appliance 200 transmitting the data, a receiver receiving the data
and the receiver transmitting the data.
At step 820, bandwidth usage of an entity, such as a sender, is
monitored over the annuity period. In one embodiment, the annuity
period comprises a predetermined annuity period. In many
embodiments, the annuity period is a predetermined duration of
time. In some embodiments, the bandwidth usage of the sender is
monitored over a relatively longer annuity period, such as a week,
a month or a year. In some embodiments, the bandwidth usage of the
sender is monitored over a relatively shorter annuity period, such
as a second, a minute, an hour, or a range of hours. In some
embodiments, the annuity period is a period of time defined by a
sender, receiver or an intermediary. In a plurality of embodiments,
the annuity period is defined by a user transmitting information or
data from the sender. In a number of embodiments, the annuity
period is defined by a user receiving information or data on the
receiver. In a plurality of embodiments, an operator of the
intermediary 200 sets the predetermined annuity period. In some
embodiments, the intermediary 200 determines the predetermined
annuity period based on the statistics of the bandwidth usage by
the sender or the receiver. In some embodiments, bandwidth measurer
450 or the bandwidth monitor 720 determines the predetermined
annuity period. In a variety of embodiments, bandwidth usage is
monitored by measuring bandwidth usage by any one of, or any
combination of: a sender transmitting the data, the sender
receiving the data, an appliance 200 receiving the data, the
appliance 200 transmitting the data, a receiver receiving the data
and the receiver transmitting the data.
At step 825, a difference between the rate of transmission of the
sender and the bandwidth usage of the sender may be determined to
fall below a predetermined threshold of the bandwidth credit. In
some embodiments, the flow controller 220 determines that a
difference between the rate of a transmission of the sender and the
bandwidth usage of the sender falls below a predetermined threshold
of the bandwidth credit. In various embodiments, the compression
engine 238, the bandwidth measurer 450, the bandwidth allocator
710, the bandwidth monitor 720, or any other component of the
intermediary 200 determines the difference between the rate of
transmission of the sender and the bandwidth usage of the sender.
In many embodiments, the predetermined threshold is a range, such
as a predetermined threshold range. The difference between the rate
of transmission and the bandwidth usage of the sender may fall
within a predetermined threshold range. In a plurality of
embodiments, the difference between the rate of transmission and
the bandwidth usage of the sender falls outside of a predetermined
threshold range. Predetermined threshold may be any value of the
bandwidth, any amount of data or any amount of data per period of
time. Predetermined threshold may be any number or a value.
Predetermined threshold range may be any range of bandwidth, any
range of data amount or any range of data amount per period of
time. In some embodiments, the intermediary 200, or any
intermediary 200 component determines that a difference between the
rate of transmission of the sender and the bandwidth usage of the
sender falls above a predetermined threshold of the bandwidth
credit. In a number of embodiments, the predetermined threshold of
the bandwidth credit is determined by comparing the amount of data
of the compressed data packets 495 to the amount of data of the
data packets 480 corresponding to the compressed data packets 495,
before the same data packets 480 were compressed by the
intermediary 200. In a number of embodiments, the predetermined
threshold of the bandwidth credit is determined by using the amount
of data of the compressed data packets 495 and the amount of data
of the data packets 480 corresponding to the compressed data
packets 495, before the same data packets 480 were compressed by
the intermediary 200. In some embodiments, the predetermined
threshold is determined by determining the compression ratios of
the compressed data packets 495 in relation to the data packets 480
corresponding to the compressed data packets 495 before being
compressed by the intermediary 200.
At step 830, a difference between the bandwidth usage of the sender
over the annuity period and the annuity of bandwidth credit may be
determined to exceed a predetermined threshold. In some
embodiments, the predetermined threshold is a predetermined
threshold of a bandwidth credit. In some embodiments, the flow
controller 220 determines that a difference between the bandwidth
usage of the sender over the annuity period and the annuity of
bandwidth credit exceeds a predetermined threshold. In various
embodiments, the compression engine 238, the bandwidth measurer
450, the bandwidth allocator 710, the bandwidth monitor 720, or any
other component of the intermediary 200 determines the difference
between the bandwidth usage of the sender over the annuity period
and the annuity of bandwidth credit. In many embodiments, the
predetermined threshold is a predetermined threshold range. The
difference between the bandwidth usage of the sender over the
annuity period and the annuity of bandwidth credit may fall within
a predetermined threshold range. In a plurality of embodiments, the
difference between the rate of transmission and the bandwidth usage
of the sender falls outside of a predetermined threshold range.
Predetermined threshold may be any value of the bandwidth, any
amount of data or any amount of data per period of time.
Predetermined threshold may be any number or a value. Predetermined
threshold range may be any range of bandwidth, any range of data
amount or any range of data amount per period of time. In some
embodiments, the intermediary 200, or any intermediary 200
component determines that a difference between the rate of
transmission of the sender and the bandwidth usage of the sender
falls above a predetermined threshold. In a number of embodiments,
the predetermined threshold is determined by comparing the amount
of data of the compressed data packets 495 to the amount of data of
the data packets 480 corresponding to the compressed data packets
495, before the same data packets 480 were compressed by the
intermediary 200. In a number of embodiments, the predetermined
threshold of the bandwidth credit is determined by using the amount
of data of the compressed data packets 495 and the amount of data
of the data packets 480 corresponding to the compressed data
packets 495, before the same data packets 480 were compressed by
the intermediary 200. In some embodiments, the predetermined
threshold is determined by determining the compression ratios of
the compressed data packets 495 in relation to the data packets 480
corresponding to the compressed data packets 495 before being
compressed by the intermediary 200.
At step 835, in response to the determination, an allocation of a
one-time bandwidth credit may be communicated to the sender based
on the difference. In some embodiments, an allocation of a one-time
bandwidth credit to a receiver is communicated. In some
embodiments, communicating an allocation of a one-time bandwidth
credit is based on the difference between the bandwidth usage of
the sender over the annuity period and the annuity of bandwidth
credit. In many embodiments, communicating an allocation of a
one-time bandwidth credit is based on the difference between the
bandwidth usage of the sender or the receiver over the annuity
period and the annuity of bandwidth credit exceeding or not
exceeding the predetermined threshold. In some embodiments,
communicating an allocation of a one-time bandwidth credit is based
on the difference between the rate of transmission of the sender or
the receiver and the bandwidth usage. In a plurality of
embodiments, communicating an allocation of a one-time bandwidth
credit is based on the difference between the rate of transmission
of the sender or the receiver and the bandwidth usage of the sender
or the receiver falling below or above a predetermined threshold of
the bandwidth credit. In some embodiments, communicating an
allocation of a one-time bandwidth credit is in response to the
determination. In a variety of embodiments, communicating an
allocation of a one-time bandwidth credit is in response to the
monitoring of the bandwidth usage. In a number of embodiments,
communicating an allocation of a one-time bandwidth credit is in
response to the monitoring of the bandwidth usage and the
determining a difference between the rate of transmission of the
sender or the receiver and the bandwidth usage of the sender or the
receiver. In many embodiments, communicating an allocation of a
one-time bandwidth credit is in response to the monitoring of the
bandwidth usage and the determining of the difference between the
bandwidth usage of the sender or the receiver over the annuity
period and the annuity of bandwidth credit.
At step 840, in response to the determination, a renewed allocation
of the annuity bandwidth credit is communicated to a sender based
on a second predetermined ratio of compression. In a number of
embodiments, a renewed allocation of the annuity bandwidth credit
to a receiver is communicated. In some embodiments, communicating a
renewed allocation of the annuity bandwidth credit is based on the
difference between the bandwidth usage of the sender or the
receiver over the annuity period and the annuity of bandwidth
credit. In many embodiments, communicating a renewed allocation of
the annuity bandwidth credit is based on the difference between the
bandwidth usage of the sender or the receiver over the annuity
period and the annuity of bandwidth credit, exceeding or not
exceeding the predetermined threshold. In some embodiments,
communicating a renewed allocation of the annuity bandwidth credit
is based on the difference between the rate of transmission of the
sender or the receiver and the bandwidth usage of the sender or the
receiver. In a plurality of embodiments, communicating an
allocation of a one-time bandwidth credit is based on the
difference between the rate of transmission of the sender or the
receiver and the bandwidth usage of the sender or the receiver
falling below or above a predetermined threshold of the bandwidth
credit. In some embodiments, communicating an allocation of a
one-time bandwidth credit is in response to the determination. In a
variety of embodiments, communicating an allocation of a one-time
bandwidth credit is in response to the monitoring of the bandwidth
usage of the sender or the receiver. In a number of embodiments,
communicating an allocation of a one-time bandwidth credit is in
response to the monitoring of the bandwidth usage and the
determining a difference between the rate of transmission of the
sender or the receiver and the bandwidth usage of the sender or the
receiver. In many embodiments, communicating an allocation of a
one-time bandwidth credit is in response to the monitoring of the
bandwidth usage and the determining of the difference between the
bandwidth usage of the sender or the receiver over the annuity
period and the annuity of bandwidth credit.
Many alterations and modifications may be made by those having
ordinary skill in the art without departing from the spirit and
scope of the disclosure. Therefore, it should be clear that any of
the embodiments presented above may be combined with any other
embodiments above for expressing any other aspects of the
disclosure. It should also be expressly understood that the
illustrated embodiments have been shown only for the purposes of
example and should not be taken as limiting the disclosure, which
is defined by the following claims. These claims are to be read as
including what they set forth literally and also those equivalent
elements which are insubstantially different, even though not
identical in other respects to what is shown and described in the
above illustrations.
* * * * *